Data retrieval method and link-information adding method

ABSTRACT

A data retrieval method in a data-string set including a plurality of data strings, each data string having a data identification name storage area, a parent data storage area storing link-information data, wherein when data strings are consecutively traced on the basis of link-information data stored in parent data storage areas of data strings, with arbitrary link-information data stored in the parent data storage area of a certain data string as a starting point, until the parent data storage area of the traced data string is empty, the link-information data about the certain data string is included in none of the parent data storage areas of the traced data strings; the method comprising recursively extracting a data string on the basis of link-information data stored in a parent data storage areas of the data string storing a data identification name to be retrieved and the extracted data string, until the parent data storage area of the extracted data string is empty.

BACKGROUND OF THE INVENTION AND RELATED ART STATEMENT

The present invention relates to a data retrieval method in a data structure which can constitute, e.g., database or an artificial intelligence, and a method of adding link-information data to a data string of the data structure.

A variety of databases are practically used at present, and above all, a relational database is the most widely used. A variety of data are stored in a database, and data stored in the database is retrieved by various methods.

With reference to an example in which each of concept names such as DESK, PENCIL, WOOD, GRAPHITE, MICA and BRUSH OF MOTOR consists of element names as shown in the following Table 1, and in a record, the concept name is stored in a concept field and element name(s) is/are stored in element field(s), the outline of a conventional relational database will be explained below. In Table 1, numerals show record numbers, and alphabets show element field numbers.

In the relational database, a new record relationship can made by deriving the relationship of X{Z} on the basis of a combination of two records of X{ . . . , Y, . . . } and Y { . . . , Z, . . . }. A capital letter located before the brace "{" stands for a concept name, and capital letters in the braces "{}" stand for element names. For example, concept name "DESK" and element name "COMBUSTIBILITY" can be combined as DESK{COMBUSTIBILITY}

on the basis of a combination of records of

DESK{WOOD, . . . }

and

WOOD { . . . , COMBUSTIBILITY, . . .

                                      TABLE 1                                      __________________________________________________________________________     Record                                                                             Concept                                                                            Element Field                                                          No. Field                                                                              A    B    C    D    E   F  G   H   I                                   __________________________________________________________________________     1   desk                                                                               wood office                                                                              furniture                                                                 supplies                                                          2   pencil                                                                             wood insulator                                                                           combusti-                                                                           conducti-                                                                           softness                                                                           black                                                                             office                                                                             writing                                                                            cylindri-                                             bility                                                                              bility   color                                                                             supplies                                                                           tools                                                                              cal form                            3   wood                                                                               insulator                                                                           combusti-                                                                           plant                                                                               specific                                                             bility    gravity of                                                                     1 or less                                               4   graphite                                                                           conducti-                                                                           softness                                                                            black                                                                bility    color                                                        5   mica                                                                               insulator                                                              6   brush of                                                                           conducti-                                                                           softness                                                                            black                                                            motor                                                                              bility    color                                                        __________________________________________________________________________

For convenience'sake, record "X" refers to a record in which concept name "X" is stored in the concept field.

In the relational database, for obtaining a piece of information that element name of "COMBUSTIBILITY" can be included in concept name "DESK", i.e., for combining record "X" including element name "Y" with record "Y" including element name "Z", it is necessary to know the number of the element field containing element name "Y" in record "X". In the example shown in Table 1, for example, it is necessary to know element name of "WOOD" is stored in element field number A of record number 1. However, the number of the element field containing element name "Y" is not always known. It is therefore necessary to combine all the element fields of record X with the concept fields of other records. However, the above operation requires enormous processing when the records and element fields increase in number. For preventing the above situation, there might be a method in which one record consists of one concept field and one element field, and the element field of the record is combined with the concept field of other records. However, not only a great number of records are required, but also it is required to input one concept name in each concept field of a great number of records.

In the relational database, further, when element name "COMBUSTIBILITY" is retrieved without combining records, record "PENCIL" and record "WOOD" are extracted. That is, a directly related concept name can be extracted. However, since the record "DESK" includes element name "WOOD" but the record "DESK" does not include element name "COMBUSTIBILITY" in its element field, it is impossible to make out a piece of information that record "DESK" can include element name "COMBUSTIBILITY". That is, an indirect related concept name can not be extracted. In the relational database, therefore, it is required to input element name "COMBUSTIBILITY" to the element field of the record "DESK". That is, the problem is that one "element name" is required to be inputted in an element field of each of a plurality of records. Further, it is required to input a number of element names in element fields in records having certain concept names. In another solution, all the element fields can be combined with all concept fields. However, it is required to retrieve huge data made by the above combinations, and it is not known which element field has the element name to be retrieved. It is therefore necessary to retrieve all the element fields.

In the relational database, further, it is impossible to prevent the occurrence of circulating definitions of A{B}, B{C} and C{A}. If the records having a state of the circulating definition are allowed to be present, an endless loop takes place in the retrieval.

In the relational database, further, original data are generally arrayed in the form of a two-dimensional table. Each column corresponds to a concept field and an element field containing fixed data of the same kind, and data are classified in advance and inputted to corresponding fields. The relational database is therefore not suitable for expressing a case where an element of an indefinite number such as concept name "PENCIL" is included and the attributes of data to be inputted in element fields are not classified.

In the above-explained relational database, the concept field is placed in the same table, while the above is also true of a case where one table is made from one concept.

OBJECTS AND SUMMARY OF THE INVENTION

It is therefore a first object of the present invention to provide a data retrieval method which enables the extraction of not only a directly related concept name but also an indirectly related concept name.

Further, it is a second object of the present invention to provide a method of adding link-information data, which enables the exclusion of occurrence of the above circulating definition when new link-information data is added to a predetermined region in a data string of a data-string set consisting of a plurality of data strings.

The data retrieval method directed to the first aspect of the present invention for achieving the above first object of the present invention is concerned with a data retrieval method of extracting a data string, which corresponds to a parent concept and/or an indirect parent concept, for a data identification name to be retrieved. The terms "parent concept" and "indirect parent concept" will be explained in detail later. That is, the data retrieval method directed to the first aspect of the present invention is a data retrieval method in a data-string set including a plurality of data strings,

each data string DS₋₋ 1 having

(1) a data identification name storage area storing a data identification name,

(2) a data level storage area storing a data level value, and

(3) a parent data storage area storing link-information data about a data string DS₋₋ 2 storing a data identification name which indicates a set including the data identification name stored in the data string DS₋₋ 1,

wherein:

(A) the data string DS₋₋ 2 has a larger data level value than the data string DS₋₋ 1 has,

(B) the parent data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the parent data storage area of the data string DS₋₋ 1 differ from one another, and

(C) when data strings are consecutively traced on the basis of link-information data stored in parent data storage areas of data strings, with arbitrary link-information data stored in the parent data storage area of the data string DS₋₋ 1 as a starting point, until the parent data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the parent data storage areas of the traced data strings,

the method comprising the steps of

(a) inputting a data identification name corresponding to data to be retrieved,

(b) extracting a data string on the basis of link-information data stored in a parent data storage area of a data string whose data identification name storage area stores the same data identification name as the inputted data identification name, and further extracting a data string on the basis of link-information data stored in a parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty, and

(c) outputting the extracted data string.

The term "link-information data" stands for a direct address or an indirect address for an area storing a data string, a pointer for an address area storing a data string, or a data identification name stored in a data string. To sum up, the link-information data may be any data which is referred to for reaching contents of other data string. The term "link-information data" is used in this sense hereinafter.

In the data retrieval method directed to the first aspect of the present invention, in the step (b), as schematically shown in FIG. 1A, data strings P₁, P₂, P₃, . . . are extracted on the basis of the link-information data stored in the parent data storage area of the data string S₀ whose data identification name storage area stores the same data identification name as the inputted data identification name. Then, concerning the data strings P₁, P₂, P₃, . . . , data strings are extracted on the basis of the link-information data stored in the parent data storage areas of these extracted data strings P₁, P₂, P₃ . . . . The extracted data strings are, for example, data string P₁₁, P₁₂, P₁₃. . . , P₂₁, P₂₂, P₂₃ . . . , P₃₁, P₃₂, P₃₃ . . . . FIGS. 1A and 1B show part of the data strings.

Then, data strings are extracted on the basis of the link-information data stored in the parent data storage areas of all of the extracted data strings P₁₁, P₁₂, P₁₃ . . . , P₂₁, P₂₂, P₂₃ . . . , P₃₁, P₃₂, P₃₃ . . . . The extracted data strings are P₁₁₁, P₁₁₂, P₁₁₃ . . . , P₁₂₁, P₁₂₂, P₁₂₃ . . . , P₁₃₁, P₁₃₂, P₁₃₃ . . . , P₂₁₁, P₂₁₂, P₂₁₃ . . . , P₂₂₁, P₂₂₂, P₂₂₃, P₂₃₁, P₂₃₂, P₂₃₃ . . . , P₃₁₁, P₃₁₂, P₃₁₃ . . . , P₃₂₁, P₃₂₂, P₃₂₃ . . . , P₃₃₁, P₃₃₂, P₃₃₃ . . . (see FIG. 1B). Then, data strings are extracted on the basis of the link-information data stored in the parent data storage areas of these extracted data strings P₁₁₁, P₁₁₂, P₁₁₃ . . . . This operation is conducted until the parent data storage areas of the extracted data strings are empty. The flow of the above operation will be referred to as "first retrieving pattern" for convenience' sake. In FIGS. 1A and 1B, symbols within ellipses stand for data strings, and numerals given to lines connecting the ellipses show the order of operation.

The above step (b) can be also conducted according to the flow of operation shown in FIG. 2 (to be referred to as "second retrieving pattern"). That is, data string P₁, is extracted on the basis of the link-information data stored in the parent data storage area of the data string S₀ storing the same data identification name as the inputted data identification name. FIG. 2 shows part of data strings.

Then, data strings are extracted on the basis of the link-information data stored in the parent data storage area of the data string P₁, until the parent data storage area of the extracted data string is empty. That is, data string P₁₁, data string P₁₁₁ and data string P₁₁₁₁ are consecutively extracted. Since the parent data storage area of the extracted data string P₁₁₁₁ is empty, the operation returns to the data string P₁₁₁, and data string P₁₁₁₂ is extracted on the basis of the link-information data stored in the next parent data storage area of the data string P₁₁₁. Since the parent data storage area of the extracted data string P₁₁₁₂ is empty, the operation returns to the data string P₁₁₁, and data string P₁₁₁₃ is extracted on the basis of the link-information data stored in the next parent data storage area of the data string P₁₁₁. Since the parent data storage area of the extracted data string P₁₁₁₃ is empty, the operation returns to the data string P₁₁₁. Since, however, the next parent data storage area of the data string P₁₁₁ is empty, the operation returns to the data string P₁₁, and data string P₁₁₂, data string P₁₁₂₁, data string P₁₁₁₂ and data string P₁₁₂₃ are consecutively extracted on the basis of the link-information data stored in the next parent data storage area of the data string P₁₁. The above procedures are consecutively conducted. And, if the link-information data stored in the parent data storage area of the data string P₁₁ is empty, data string is extracted on the basis of the link-information data stored in the next parent data storage area of the data string P₁. Further, if the link-information data stored in the parent data storage area of the data string P₁ is empty, data strings P₂, P₃, . . . are extracted on the basis of the link-information data stored in the next parent data storage area of the data string S₀. In FIG. 2, symbols within ellipses stand for data strings, and numerals given to lines connecting the ellipses show the order of operation.

The data retrieval method directed to the second aspect of the present invention for achieving the above first object of the present invention is concerned with a data retrieval method of extracting a data string, which corresponds to an element concept and/or an indirect element concept, for a data identification name to be retrieved. The terms "element concept" and "indirect element concept" will be explained in detail later. That is, the data retrieval method directed to the second aspect of the present invention is a data retrieval method in a data-string set including a plurality of data strings,

each data string DS₋₋ 1 having

(1) a data identification name storage area storing a data identification name,

(2) a data level storage area storing a data level value, and

(3) an element data storage area storing link-information data about a data string DS₋₋ 0 storing a data identification name which is an element of a set indicated by the data identification name stored in the data string DS₋₋ 1,

wherein:

(A) the data string DS₋₋ 0 has a smaller data level value than the data string DS₋₋ 1 has,

(B) the element data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the element data storage area of the data string DS₋₋ 1 differ from one another, and

(C) when data strings are consecutively traced on the basis of link-information data stored in element data storage areas of data strings, with arbitrary link-information data stored in the element data storage area of the data string DS₋₋ 1 as a starting point, until the element data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the element data storage areas of the traced data strings,

the method comprising the steps of

(a) inputting a data identification name corresponding to data to be retrieved,

(b) extracting a data string on the basis of link-information data stored in an element data storage area of a data string whose data identification name storage area stores the same data identification name as the inputted data identification name, and further extracting a data string on the basis of link-information data stored in an element data storage area of the extracted data string until the element data storage area of the extracted data string is empty, and

(c) outputting the extracted data string.

In the data retrieval method directed to the second aspect of the present invention, as shown in FIG. 3A, in the step (b), data strings E₁, E₂, E₃, . . . are extracted on the basis of the link-information data stored in the element data storage area of the data string S₀ whose data identification name storage area stores the same data identification name as the inputted data identification name. Then, concerning the data strings E₁, E₂, E₃, . . . data strings are extracted on the basis of the link-information data stored in the element data storage areas of these extracted data strings E₁, E₂, E₃, . . . . The extracted data strings are, for example, data strings E₁₁, E₁₂, E₁₃ . . . , E₂₁, E₂₂, E₂₃ . . . , E₃₁, E₃₂, E₃₃ . . . . FIGS. 3A and 3B show part of the data strings.

Then, data strings are extracted on the basis of the link-information data stored in the element data storage areas of all of the extracted data strings E₁₁, E₁₂, E₁₃ . . . , E₂₁, E₂₂, E₂₃ . . . , E₃₁, E₃₂, E₃₃ . . . . The extracted data strings are E₁₁₁, E₁₁₂, E₁₁₃ . . . , E₁₂₁, E₁₂₂, E₁₂₃ . . . , E₁₃₁, E₁₃₂, E₁₃₃ . . . , E₂₁₁, E₂₁₂, E₂₁₃ . . . , E₂₁₁, E₂₁₂, E₂₁₃ . . . , E₂₂₁, E₂₂₂, E₂₂₃ . . . , E₂₃₁, E₂₃₂, E₂₃₃ . . . , E₃₁₁, E₃₁₂, E₃₁₃ . . . , E₃₂₁, E₃₂₂, E₃₂₃ . . . , E₃₃₁, E₃₃₂, E₃₃₃ . . . (see FIG. 3B). Then, data strings are extracted on the basis of the link-information data stored in the element data storage areas of these data strings E₁₁₁, E₁₁₂, E₁₁₃ . . . . This operation is conducted until the element data storage areas of the extracted data strings are empty. The flow of the above operation will be referred to as "third retrieving pattern" for convenience' sake. In FIGS. 3A and 3B, symbols within ellipses stand for data strings, and numerals given to lines connecting the ellipses show the order of operation.

The above step (b) can be also conducted according to the flow of operation shown in FIG. 4 (to be referred to as "fourth retrieving pattern"). That is, data string E₁ is extracted on the basis of the link-information data stored in the element data storage area of the data string S₀ storing the same data identification name as the inputted data identification name. FIG. 4 shows part of data strings.

Then, data strings are extracted on the basis of the link-information data stored in the element data storage area of the data string E₁ until the element data storage area of the extracted data string is empty. That is, data string E₁₁, data string E₁₁₁ and data string E₁₁₁₁ are consecutively extracted. Since the element data storage area of the extracted data string E₁₁₁₁ is empty, the operation returns to the data string E₁₁₁, and data string E₁₁₁₂ is extracted on the basis of the link-information data stored in the next element data storage area of the data string E₁₁₁. Since the element data storage area of the extracted data string E₁₁₁₂ is empty, the operation returns to the data string E₁₁₁, and data string E₁₁₁₃ is extracted on the basis of the link-information data stored in the next element data storage area of the data string E₁₁₁. Since the element data storage area of the extracted data string E₁₁₁₃ is empty, the operation returns to the data string E₁₁₁. Since, however, the next element data storage area of the data string E₁₁₁ is empty, the operation returns to the data string E₁₁. And, data string E₁₁₂, data string E₁₁₂₁, data string E₁₁₂₂ and data string E₁₁₂₃ are consecutively extracted on the basis of the link-information data stored in the next element data storage area of the data string E₁₁. The above procedures are consecutively conducted. And, if the link-information data stored in the element data storage area of the data string E₁₁, is empty, data string is extracted on the basis of the link-information data stored in the next element data storage area of the data string E₁. Further, if the link-information data stored in the element data storage area of the data string E₁ is empty, data strings E₂, E₃, . . . are extracted on the basis of the link-information data stored in the next element data storage area of the data string S₀.

The data retrieval method directed to the third aspect of the present invention for achieving the above first object of the present invention is concerned with a data retrieval method of extracting at least one of a data string corresponding to a parent concept, a data string corresponding to an indirect parent concept, a data string corresponding to an element concept and a data string corresponding to an indirect an element concept. That is, the data retrieval method directed to the third aspect of the present invention is a data retrieval method in a data-string set including a plurality of data-strings,

each data string DS₋₋ 1 having

(1) a data identification name storage area storing a data identification name,

(2) a data level storage area storing a data level value,

(3) a parent data storage area storing link-information data about a data string DS--2 storing a data identification name which indicates a set including the data identification name stored in the data string DS₋₋ 1, and

(4) an element data storage area storing link-information data about a data string DS₋₋ 0 storing a data identification name which is an element of a set indicated by the data identification name stored in the data string DS₋₋ 1,

wherein:

(A) the data string DS₋₋ 2 has a larger data level value than the data string DS₋₋ 1 has,

(B) the parent data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the parent data storage area of the data string DS₋₋ 1 differ from one another,

(C) when data strings are consecutively traced on the basis of link-information data stored in parent data storage areas of data strings, with arbitrary link-information data stored in the parent data storage area of the data string DS₋₋ 1 as a starting point, until the parent data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the parent data storage areas of the traced data strings,

(D) the data string DS₋₋ 0 has a smaller data level value than the data string DS₋₋ 1 has,

(E) the element data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the element data storage area of the data string DS₋₋ 1 differ from one another, and

(F) when data strings are consecutively traced on the basis of link-information data stored in element data storage areas of data strings, with arbitrary link-information data stored in the element data storage area of the data string DS₋₋ 1 as a starting point, until the element data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the element data storage areas of the traced data strings,

the method comprising the steps of

(a) inputting a data identification name corresponding to data to be retrieved,

(b) extracting a data string on the basis of link-information data stored in a parent data storage area of a data string whose data identification name storage area stores the same data identification name as the inputted data identification name, and further extracting a data string on the basis of link-information data stored in a parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty,

(c) extracting a data string on the basis of link-information data stored in an element data storage area of the data string whose data identification name storage area stores the same data identification name as the inputted data identification name, and further extracting a data string on the basis of link-information data stored in an element data storage area of the extracted data string until the element data storage area of the extracted data string is empty, and

(d) outputting the extracted data strings.

The flow of the data retrieval operation in the data retrieval method directed to the third aspect of the present invention can be conducted by properly combining the first retrieving pattern or the second retrieving pattern explained concerning the data retrieval method directed to the first aspect of the present invention with the third retrieving pattern or the fourth retrieving pattern explained concerning the data retrieval method directed to the second aspect of the present invention, and the detailed explanation thereof is omitted.

The data retrieval method directed to the fourth aspect of the present invention for achieving the above first object of the present invention is concerned with a data retrieval method of extracting a data string, which corresponds to an element concept and/or an indirect element concept and has a minimum data level value, for a data identification name to be retrieved, and then extracting a data string, which corresponds to a parent concept and/or an indirect parent concept, for the data identification name stored in the above-extracted data string. That is, the data retrieval method directed to the fourth aspect of the present invention comprises the steps of

(a) inputting a data identification name corresponding to data to be retrieved,

(b) extracting a data string on the basis of link-information data stored in an element data storage area of a data string whose data identification name storage area stores the same data identification name as the data identification name to be retrieved, and further extracting a data string on the basis of link-information data stored in an element data storage area of the extracted data string until the element data storage area of the extracted data string is empty,

(c) extracting a data string on the basis of link-information data stored in the parent data storage area of the extracted data string whose element data storage area is empty, from among the data strings extracted in the step (b), and further extracting a data string on the basis of link-information data stored in a parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty, and

(d) outputting the extracted data string.

In the data retrieval method directed to the fourth aspect of the present invention, the data-string set can be structurally the same as the data-string set in the data retrieval method directed to the above third aspect of the present invention.

In the data retrieval method directed to the fourth aspect of the present invention, the flow of the retrieval operation in the step (b) can be the third retrieving pattern or the fourth retrieving pattern explained concerning the data retrieval method directed to the second aspect of the present invention. Further, the flow of the retrieval operation in the step (c) can be the first retrieving pattern or the second retrieving pattern explained concerning the data retrieval method directed to the first aspect of the present invention. Therefore, the detailed explanation thereof are omitted.

The link-information adding method directed to the first aspect of the present invention for achieving the above second object of the present invention is concerned with a method of adding new link-information data to a parent data storage area of a data string DS₋₋ I. The new link-information is concerned with a data string DS₋₋ P corresponding to a parent concept for the data string DS₋₋ I. That is, the link-information adding method directed to the first aspect of the present invention is a link-information adding method of adding new link-information data to a parent data storage area of a data string DS₋₋ I in a data-string set consisting of a plurality of data strings,

each data string DS₋₋ 1 having

(1) a data identification name storage area storing a data identification name,

(2) a data level storage area storing a data level value, and

(3) a parent data storage area storing link-information data about a data string DS₋₋ 2 storing the data identification name which indicates a set including the data identification name stored in the data string DS₋₋ 1,

wherein:

(A) the data string DS₋₋ 2 has a greater data level value than the data string DS₋₋ 1 has,

(B) the parent data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the parent data storage area of the data string DS₋₋ 1 differ from one another, and

(C) when data strings are consecutively traced on the basis of link-information data stored in parent data storage areas of data strings, with arbitrary link-information data stored in the parent data storage area of the data string DS₋₋ 1 as a starting point, until the parent data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the parent data storage areas of the traced data strings,

the method comprising the steps of

(a) inputting a data identification name and a parent concept name which indicates a set including the data identification name,

(b) adding no link-information data when the inputted data identification name and the inputted parent concept name are in agreement with each other,

(c) extracting a data string DS₋₋ I storing the inputted data identification name when the inputted data identification name and the inputted parent concept name are not in agreement with each other,

(d) extracting a data string DS₋₋ P storing the data identification name which is in agreement with the inputted parent concept name,

(e) adding no link-information data when the parent data storage area of the data string DS₋₋ I extracted in the step (c) has link-information data about the data string DS₋₋ P extracted in the step (d),

(f) extracting a data string on the basis of link-information data stored in the parent data storage area of the data string DS₋₋ P extracted in the step (d) when the parent data storage area of the data string DS₋₋ I extracted in the step (c) has no link-information data about the data string DS₋₋ P extracted in the step (d), and further extracting a data string on the basis of the link-information data stored in the parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty,

(g) adding no link-information data when any one of the data strings extracted in the step (f) is in agreement with the data string DS₋₋ I extracted in the step (c),

(h) storing link-information data about the data string DS₋₋ P extracted in the step (d) to the parent data storage area of the data string DS₋₋ I extracted in the step (c) when none of the data strings extracted in the step (f) is in agreement with the data string DS₋₋ I extracted in the step (c), and

(i) storing a value obtained by adding 1 to the data level value of the data string DS₋₋ I extracted in the step (c) in the data level storage area of the data string DS₋₋ P extracted in the step (d) when the data string DS₋₋ P extracted in the step (d) has a data level value equal to, or smaller than, the data level value of the data string DS₋₋ I extracted in the step (c).

In the link-information adding method directed to the first aspect of the present invention, the procedures of extracting data strings in the step (f) can be the same as the first retrieving pattern or the second retrieving pattern explained concerning the data retrieval method directed to the first aspect of the present invention.

The link-information adding method directed to the second aspect of the present invention for achieving the above second object of the present invention is concerned with a method of adding new link-information data to an element data storage area of a data string DS₋₋ I. The new link-information data is concerned with a data string DS₋₋ E corresponding to an element concept for the data string DS₋₋ I. That is, the link-information adding method directed to the second aspect of the present invention is a link-information adding method of adding new link-information data to an element data storage area of a data string DS₋₋ I in a data-string set consisting of a plurality of data strings,

each data string DS₋₋ 1 having

(1) a data identification name storage area storing a data identification name,

(2) a data level storage area storing a data level value, and

(3) an element data storage area storing link-information data about a data string DS₋₋ 0 storing a data identification name which is an element of a set indicated by the data identification name stored in the data string DS₋₋ 1,

wherein:

(A) the data string DS₋₋ 0 has a smaller data level value than the data string DS₋₋ 1 has,

(B) the element data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the element data storage area of the data strings DS₋₋ 1 differ from one another, and

(C) when data strings are consecutively traced on the basis of link-information data stored in element data storage areas of data strings, with arbitrary link-information data stored in the element data storage area of the data string DS₋₋ 1 as a starting point, until the element data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the element data storage areas of the traced data strings,

the method comprising the steps of

(a) inputting a data identification name and an element concept name which is an element of a set indicated by the data identification name,

(b) adding no link-information data when the inputted data identification name and the inputted element concept name are in agreement with each other,

(c) extracting a data string DS₋₋ I storing the inputted data identification name when the inputted data identification name and the inputted element concept name are not in agreement with each other,

(d) extracting a data string DS₋₋ E storing the data identification name which is in agreement with the inputted element concept name,

(e) adding no link-information data when the element data storage area of the data string DS₋₋ I extracted in the step (c) has link-information data about the data string DS₋₋ E extracted in the step (d),

(f) extracting a data string on the basis of link-information data stored in the element data storage area of the data string DS₋₋ E extracted in the step (d) when the element data storage area of the data string DS₋₋ I extracted in the step (c) has no link-information data about the data string DS₋₋ E extracted in the step (d), and further extracting a data string on the basis of the link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty,

(g) adding no link-information data when any one of the data strings extracted in the step (f) is in agreement with the data string DS₋₋ extracted in the step (c),

(h) storing link-information data about the data string DS₋₋ E extracted in the step (d) to the element data storage area of the data string DS₋₋ I extracted in the step (c) when none of the data strings extracted in the step (f) is in agreement with the data string DS₋₋ I extracted in the step (c), and

(i) storing a value obtained by adding 1 to the data level value of the data string DS₋₋ E extracted in the step (d) in the data level storage area of the data string DS₋₋ I extracted in the step (c) when the data string DS₋₋ E extracted in the step (d) has a data level value equal to, or greater than, the data level value of the data string DS₋₋ I extracted in the step (c).

In the link-information adding method directed to the second aspect of the present invention, the procedures of extracting data strings in the step (f) can be the same as the third retrieving pattern or the fourth retrieving pattern explained concerning the data retrieval method directed to the second aspect of the present invention.

The link-information adding method directed to the third aspect of the present invention for achieving the above second object of the present invention is concerned with a method of adding new link-information data to a parent data storage area of a data string DS₋₋ I. The new link-information data is concerned with a data string DS₋₋ P corresponding to a parent concept for the data string DS₋₋ I. That is, the link-information adding method directed to the third aspect of the present invention is a link-information adding method of adding link-information data to a parent data storage area of a data string DS₋₋ I in a data-string set consisting of a plurality of data strings,

each data string DS₋₋ 1 having

(1) a data identification name storage area storing a data identification name,

(2) a data level storage area storing a data level value,

(3) a parent data storage area storing link-information data about a data string DS₋₋ 2 storing a data identification name which indicates a set including the data identification name stored in the data string DS₋₋ 1, and

(4) an element data storage area storing link-information data about a data string DS₋₋ 0 storing a data identification name which is an element of a set indicated by the data identification name stored in the data string DS₋₋ 1,

wherein:

(A) the data string DS₋₋ 2 has a greater data level value than the data string DS₋₋ 1 has,

(B) the parent data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the parent data storage area of the data string DS₋₋ 1 differ from one another,

(C) when data strings are consecutively traced on the basis of link-information data stored in parent data storage areas of data strings, with arbitrary link-information data stored in the parent data storage area of the data string DS₋₋ 1 as a starting point, until the parent data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the parent data storage areas of the traced data strings,

(D) the data string DS₋₋ 0 has a smaller data level value than the data string DS₋₋ 1 has,

(E) the element data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the element data storage area of the data strings DS₋₋ 1 differ from one another, and

(F) when data strings are consecutively traced on the basis of link-information data stored in element data storage areas of data strings, with arbitrary link-information data stored in the element data storage area of the data string DS₋₋ 1 as a starting point, until the element data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the element data storage areas of the traced data strings,

the method comprising the steps of

(a) inputting a data identification name and a parent concept name which indicates a set including the data identification name,

(b) adding no link-information data when the inputted data identification name and the inputted parent concept name are in agreement with each other,

(c) extracting a data string DS₋₋ I storing the inputted data identification name when the inputted data identification name and the inputted parent concept name are not in agreement with each other,

(d) extracting a data string DS₋₋ P storing the data identification name which is in agreement with the inputted parent concept name,

(e) adding no link-information data when the parent data storage area of the data string DS₋₋ I extracted in the step (c) has link-information data about the data string DS₋₋ P extracted in the step (d),

(f) extracting a data string on the basis of link-information data stored in the parent data storage area of the data string DS₋₋ P extracted in the step (d) when the parent data storage area of the data string DS₋₋ I extracted in the step (c) has no link-information data about the data string DS₋₋ P extracted in the step (d), and further extracting a data string on the basis of the link-information data stored in the parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty,

(g) adding no link-information data when any one of the data strings extracted in the step (f) is in agreement with the data string extracted DS₋₋ I in the step (c),

(h) storing link-information data about the data string DS₋₋ P extracted in the step (d) in the parent data storage area of the data string DS₋₋ I extracted in the step (c) when none of the data strings extracted in the step (f) is in agreement with the data string DS₋₋ I extracted in the step (c),

(i) storing link-information data about the data string DS₋₋ I extracted in the step (c) in the element data storage area of the data string DS₋₋ P extracted in the step (d), and

(j) storing a value obtained by adding 1 to the data level value of the data string DS₋₋ I extracted in the step (c) in the data level storage area of the data string DS₋₋ P extracted in the step (d) when the data string DS₋₋ P extracted in the step (d) has a data level value equal to, or smaller than, the data level value of the data string DS₋₋ I extracted in the step (c).

In the link-information adding method directed to the third aspect of the present invention, the procedures of extracting data strings in the step (f) can be the same as the first retrieving pattern or the second retrieving pattern explained concerning the data retrieval method directed to the first aspect of the present invention. In the steps (e) and (f), it is decided whether or not the parent data storage area of the data string DS₋₋ I extracted in the step (c) has the link-information data about the data string DS₋₋ P extracted in the step (d), which decision is equivalent to a decision on whether or not the element data storage area of the data string DS₋₋ P extracted in the step (d) has the link-information data about the data string DS₋₋ I extracted in the step (c).

In the above link-information adding method directed to the third aspect of the present invention, in the step (f), a data string is extracted on the basis of link-information data stored in the parent data storage area of the data string DS₋₋ P storing the inputted parent concept name. On the other hand, in the link-information adding method directed to the fourth aspect of the present invention to be explained below, in the step (f'), a data string is extracted on the basis of link-information data stored in the element data storage area of the data string DS₋₋ I storing an inputted data identification name.

That is, differing from the link-information adding method directed to the third aspect of the present invention comprising the above steps (e), (f), (g) and (h), the link-information adding method directed to the fourth aspect of the present invention for achieving the second object of the present invention comprises

(e') adding no link-information data when the element data storage area of the data string DS₋₋ P extracted in the step (d) has link-information data about the data string DS₋₋ I extracted in the step (c),

(f') extracting a data string on the basis of link-information data stored in the element data storage area of the data string DS₋₋ I extracted in the step (c) when the element data storage area of the data string DS₋₋ P extracted in the step (d) has no link-information data about the data string DS₋₋ I extracted in the step (c), and further extracting a data string on the basis of the link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty,

(g') adding no link-information data when any one of the data strings extracted in the step (f') is in agreement with the data string DS₋₋ P extracted in the step (d) and

(h') storing link-information data about the data string DS₋₋ P extracted in the step (d) in the parent data storage area of the data string DS₋₋ I extracted in the step (c) when none of the data strings extracted in the step (f') is in agreement with the data string DS₋₋ P extracted in the step (d).

In the link-information adding method directed to the fourth aspect of the present invention, the procedures of extracting a data string in the step (f') can be the same as the third retrieving pattern or the fourth retrieving pattern explained concerning the data retrieval method directed to the second aspect of the present invention. In the steps (e') and (f'), it is decided whether or not the element data storage area of the data string DS₋₋ P extracted in the step (d) has the link-information data about the data string DS₋₋ I extracted in the step (c), which decision is equivalent to a decision on whether or not the parent data storage area of the data string DS₋₋ I extracted in the step (c) has the link-information data about the data string DS₋₋ P extracted in the step (d).

In the above link-information adding methods directed to the third and fourth aspects of the present invention, a data identification name and a parent concept name indicating a set including the data identification name are inputted. On the other hand, in the following link-information adding methods directed to the fifth and sixth aspects of the present invention, a data identification name and an element concept name which is an element of a set indicated by the data identification name are inputted.

The link-information adding method directed to the fifth aspect of the present invention for achieving the above second object of the present invention is concerned with a link-information adding method of adding new link-information data to an element data storage area of a data string DS₋₋ I. The new link-information data is concerned with a data string DS₋₋ E corresponding to an element concept for the data string DS₋₋ I. That is, the link-information adding method directed to the fifth aspect of the present invention is a link-information adding method of adding new link-information data to an element data storage area of a data string DS₋₋ I in a data-string set consisting of a plurality of data strings,

each data string DS₋₋ 1 having

(1) a data identification name storage area storing a data identification name,

(2) a data level storage area storing a data level value,

(3) a parent data storage area storing link-information data about a data string DS₋₋ 2 storing the data identification name which indicates a set including the data identification name stored in the data string DS₋₋ 1, and

(4) an element data storage area storing link-information data about a data string DS₋₋ 0 storing the data identification name which is an element of a set indicated by the data identification name stored in the data string DS₋₋ 1,

wherein:

(A) the data string DS₋₋ 2 has a greater data level value than the data string DS₋₋ 1 has,

(B) the parent data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the parent data storage area of the data string DS₋₋ 1 differ from one another,

(C) when data strings are consecutively traced on the basis of link-information data stored in parent data storage areas of data strings, with arbitrary link-information data stored in the parent data storage area of the data string DS₋₋ 1 as a starting point, until the parent data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the parent data storage areas of the traced data strings,

(D) the data string DS₋₋ 0 has a smaller data level value than the data string DS₋₋ 1 has,

(E) the element data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the element data storage area of the data string DS₋₋ 1 differ from one another, and

(F) when data strings are consecutively traced on the basis of link-information data stored in element data storage areas of data strings, with arbitrary link-information data stored in the element data storage area of the data string DS₋₋ 1 as a starting point, until the element data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the element data storage areas of the traced data strings,

the method comprising the steps of

(a) inputting a data identification name and an element concept name which is an element of a set indicated by the data identification name,

(b) adding no link-information data when the inputted data identification name and the inputted element concept name are in agreement with each other,

(c) extracting a data string DS₋₋ I storing the inputted data identification name when the inputted data identification name and the inputted element concept name are not in agreement with each other,

(d) extracting a data string DS₋₋ E storing the data identification name which is in agreement with the inputted element concept name,

(e) adding no link-information data when the element data storage area of the data string DS₋₋ I extracted in the step (c) has link-information data about the data string DS₋₋ E extracted in the step (d),

(f) extracting a data string on the basis of link-information data stored in the parent data storage area of the data string DS₋₋ I extracted in the step (c) when the element data storage area of the data string DS₋₋ I extracted in the step (c) has no link-information data about the data string DS₋₋ E extracted in the step (d), and further extracting a data string on the basis of the link-information data stored in the parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty,

(g) adding no link-information data when any one of the data strings extracted in the step (f) is in agreement with the data string DS₋₋ E extracted in the step (d),

(h) storing link-information data about the data string DS₋₋ E extracted in the step (d) in the element data storage area of the data string DS₋₋ I extracted in the step (c) when none of the data strings extracted in the step (f) is in agreement with the data string DS₋₋ E extracted in the step (d),

(i) storing link-information data about the data string DS₋₋ I extracted in the step (c) in the parent data storage area of the data string DS₋₋ E extracted in the step (d), and

(j) storing a value obtained by adding 1 to the data level value of the data string DS₋₋ E extracted in the step (d) in the data level storage area of the data string DS₋₋ I extracted in the step (c) when the data string DS₋₋ E extracted in the step (d) has a data level value equal to, or greater than, the data level value of the data string DS₋₋ I extracted in the step (c).

In the link-information adding method directed to the fifth aspect of the present invention, the procedures of extracting data strings in the step (f) can be the same as the first retrieving pattern or the second retrieving pattern explained concerning the data retrieval method directed to the first aspect of the present invention. In the steps (e) and (f), it is decided whether or not the element data storage area of the data string DS₋₋ I extracted in the step (c) has the link-information data about the data string DS₋₋ E extracted in the step (d), which decision is equivalent to a decision on whether or not the parent data storage area of the data string DS₋₋ E extracted in the step (d) has the link-information data about the data string DS₋₋ I extracted in the step (c).

In the above link-information adding method directed to the fifth aspect of the present invention, in the step (f), a data string is extracted on the basis of link-information data stored in the parent data storage area of the data string DS₋₋ I storing the inputted data identification name. On the other hand, in the link-information adding method directed to the sixth aspect of the present invention to be explained below, in the step (f'), a data string is extracted on the basis of link-information data stored in the element data storage area of the data string DS₋₋ E storing the inputted element concept name.

That is, differing from the link-information adding method directed to the fifth aspect of the present invention comprising the above steps (e), (f), (g) and (h), the link-information adding method directed to the sixth aspect of the present invention for achieving the second object of the present invention comprises

(e') adding no link-information data when the parent data storage area of the data string DS₋₋ E extracted in the step (d) has link-information data about the data string DS₋₋ I extracted in the step (c),

(f') extracting a data string on the basis of link-information data stored in the element data storage area of the data string DS₋₋ E extracted in the step (d) when the parent data storage area of the data string DS₋₋ E extracted in the step (d) has no link-information data about the data string DS₋₋ I extracted in the step (c), and further extracting a data string on the basis of link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty,

(g') adding no link-information data when any one of the data strings extracted in the step (f') is in agreement with the data string DS₋₋ extracted in the step (c), and

(h') storing link-information data about the data string DS₋₋ E extracted in the step (d) in the element data storage area of the data string DS₋₋ I extracted in the step (c) when none of the data strings extracted in the step (f') is in agreement with the data string DS₋₋ I extracted in the step (c).

In the link-information adding method directed to the sixth aspect of the present invention, the data-string set can be structurally the same as the data-string set in the above link-information adding method directed to the fifth aspect of the present invention.

In the link-information adding method directed to the sixth aspect of the present invention, the procedures of extracting data strings in the step (f') can be the same as the third retrieving pattern or the fourth retrieving pattern explained concerning the data retrieval method directed to the second aspect of the present invention. In the steps (e') and (f'), it is decided whether or not the parent data storage area of the data string DS₋₋ E extracted in the step (d) has the link-information data about the data string DS₋₋ I extracted in the step (c), which decision is equivalent to a decision on whether or not the element data storage area of the data string DS₋₋ I extracted in the step (c) has the link-information data about the data string DS₋₋ E extracted in the step (d).

In the data retrieval method or the link-information adding method of the present invention, the parent data storage area (or the element data storage area) of the data string DS₋₋ 1 contains no link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the parent data storage area (or the element data storage area) of the data string DS₋₋ 1 differ from one another. Further, when data strings are consecutively traced on the basis of link-information data stored in parent data storage areas (or element data storage areas) of data strings, with arbitrary link-information data stored in the parent data storage area (or the element data storage area) of the data string DS₋₋ 1 as a starting point, until the parent data storage area (or the element data storage area) of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the parent data storage areas (or element data storage areas) of the traced data strings. Therefore, not only the possibility of falling into an endless loop can be completely prevented, but also the circulating definition to be described later can be completely excluded.

In the data retrieval method of the present invention, further, a data string is extracted on the basis of the link-information data stored in the parent data storage area (or the element data storage area) of the data string whose data identification name storage area stores the inputted data identification name, and a data string is extracted on the basis of the link-information data stored in the parent data storage area (or the element data storage area) of the extracted data string until the parent data storage area (or the element data storage area) of the extracted data string is empty. Therefore, not only the data string corresponding to a parent concept (or an element concept) but also the data string corresponding to an indirect parent concept (or an indirect element concept) can be extracted. Unlike prior art, it is no longer necessary to store an element name in a plurality of element fields repeatedly.

In the link-information adding method of the present invention, in the step (f) or (f'), a data string is extracted and it is decided whether or not the extracted data string stores the link-information data about the data string storing the inputted parent concept name (or the inputted element concept name). As a result, when link-information data is added, the possibility of falling into an endless loop in the retrieval can be completely prevented, and the circulating definition to be described later can be completely excluded.

BRIEF DESCRIPTION OF THE DRAWINGS

The present invention will be explained in detail with reference to drawings hereinafter.

FIGS. 1A and 1B schematically show the first retrieving pattern in the data retrieval method directed to the first aspect of the present invention.

FIG. 2 schematically shows the second retrieving pattern in the data retrieval method directed to the first aspect of the present invention.

FIGS. 3A and 3B schematically show the third retrieving pattern in the data retrieval method directed to the second aspect of the present invention.

FIG. 4 schematically shows the fourth retrieving pattern in the data retrieval method directed to the second aspect of the present invention.

FIGS. 5A and 5B schematically show the structure of a data string of each level and the structure of a first level data string in Example 1.

FIGS. 6A and 6B schematically show the structures of second and third level data strings in Example 1.

FIGS. 7A and 7B schematically show the structures of second and third level data strings in Example 1.

FIG. 8 is a flow chart showing the data retrieval method in Example 1.

FIG. 9 is a flow chart showing the retrieving process-1 in the data retrieval method in Example 1.

FIG. 10 is a flow chart showing the data retrieval method in Example 2.

FIG. 11 is a flow chart showing the retrieving process-2 in the data retrieval method in Example 2.

FIG. 12 shows the order of procedures of the retrieving process-2 in the data retrieval method in Example 2.

FIG. 13 is a flow chart showing the data retrieval method in Example 3.

FIG. 14 is a flow chart showing the data retrieval method in Example 3 subsequent to FIG. 13.

FIG. 15 is a flow chart showing the link-information adding method in Example 4.

FIG. 16 is a flow chart showing the adjustment of data level value in the link-information adding method in Example 4.

FIG. 17 is a flow chart showing the link-information adding method in Example 4 subsequent to FIG. 15.

FIG. 18 is a flow chart showing the link-information adding method in Example 4 subsequent to FIG. 17.

FIGS. 19A and 19B schematically show the structure of a data string of each level and the structure of a first level data string in Example 5.

FIGS. 20A and 20B schematically show the structures of second and third level data strings in Example 5.

FIGS. 21A and 21B schematically show the structures of second and third level data strings in Example 5.

FIG. 22 is a flow chart showing the data retrieval method in Example 5.

FIG. 23 is a flow chart showing the retrieving process-3 in the data retrieval method in Example 5.

FIG. 24 is a flow chart showing the data retrieval method in Example 6.

FIG. 25 is a flow chart showing the link-information adding method in Example 7.

FIG. 26 is a flow chart showing the adjustment of data level value in the link-information adding method in Example 7.

FIG. 27 schematically shows the structure of a data string of each level in Example 8.

FIG. 28 schematically shows the structure of a first level data string in Example 8.

FIG. 29 schematically shows the structure of a second level data string in Example 8.

FIG. 30 schematically shows the structure of a third level data string in Example 8.

FIG. 31 schematically shows the structure of a second level data string in Example 8.

FIG. 32 schematically shows the structure of a third level data string in Example 8.

FIG. 33 schematically shows another example of the structure of a data string of each level in the present invention.

FIG. 34 schematically shows an apparatus suitable for working the data retrieval method of the present invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS

The present invention will be explained with reference to Examples hereinafter. First, the background of the data retrieval method and the link-information adding method of the present invention will be explained first, followed by the explanation of specific examples of the data retrieval method and the link-information adding method of the present invention.

In the data structure shown in Table 1, for example, element name "COMBUSTIBILITY" is stored in record "PENCIL" and record "WOOD", and "WOOD" is stored in the element field of record "DESK". Therefore, if not only record "PENCIL" and record "WOOD" are extracted but also record "DESK" containing "WOOD" in its element field can be extracted when the record containing element name "COMBUSTIBILITY" in its element field is retrieved, it is not necessary to store element name "COMBUSTIBILITY" in the element field of record "DESK".

Further, element name "CONDUCTIBILITY", element name "SOFTNESS" and element name "BLACK COLOR" are stored in the element fields of record "PENCIL" and record "BRUSH OF MOTOR". All of these element names are stored in record "GRAPHITE". Therefore, if element name "GRAPHITE" is stored in the element fields of record "PENCIL" and record "BRUSH OF MOTOR", and if not only record "GRAPHITE" but also record "PENCIL" and record "BRUSH OF MOTOR" can be extracted when the record having the element field containing any one (e.g., element name "BLACK COLOR") of the element names stored in "GRAPHITE" is retrieved, element name "CONDUCTIBILITY", element name "SOFTNESS" and element name "BLACK COLOR" can be deleted from the element fields of record "PENCIL" and record "BRUSH OF MOTOR". In other words, it is not necessary to store element name "CONDUCTIBILITY", element name "SOFTNESS" and element name "BLACK COLOR" in the element fields of record "PENCIL" and record "BRUSH OF MOTOR".

Similarly, the element fields of record "PENCIL" store element name "INSULATOR" and element name "COMBUSTIBILITY", and these element names are also contained in record "WOOD". Therefore, when the record having the element field containing any one (e.g., element name "COMBUSTIBILITY") of the element names stored in record "WOOD" is retrieved and if the record "PENCIL" having the element field containing "WOOD" can be extracted as well, element name "COMBUSTIBILITY" can be deleted from the element field of record "PENCIL". Further, it is no longer necessary to store element names constituting record "WOOD" such as element name "INSULATOR", element name "PLANT" and element name "SPECIFIC GRAVITY OF 1 OR LESS" in the element fields of record "DESK" and record "PENCIL".

If it is no longer necessary to store one element name in a plurality of element fields repeatedly as explained above, it is made more effective to input data. Further, concepts can be grouped into various levels such as lower concepts, intermediate concepts and higher concepts. Table 2 shows data strings which are simplified as explained above.

The background of the data retrieval method and the link-information adding method of the present invention will be explained first with reference to Table 2. Concepts shown in Table 2 are interpreted most simply below. That is, concept "DESK" is a set including elements {WOOD, OFFICE SUPPLIES, FURNITURE}. Concept "PENCIL" is a set including elements {WOOD, GRAPHITE, OFFICE SUPPLIES, WRITING TOOLS, CYLINDRICAL FORM}. Concept "WOOD" is a set including elements {INSULATOR, COMBUSTIBILITY, PLANT, SPECIFIC GRAVITY OF 1 OR LESS}. Concept "GRAPHITE" is a set including elements {CONDUCTIBILITY, SOFTNESS, BLACK COLOR}. Concept "MICA" is a set including element {INSULATOR}. Concept "BRUSH OF MOTOR" is a set including element {GRAPHITE}.

Originally, a concept is established by defining it by some qualities. A concept can be therefore identified by enumerating qualities defining the concept. A "set" in terms of mathematics can be determined by enumerating elements included in the set. A set is therefore suitable as a model of a concept. A set can contain another set as an element. That is, concept "PENCIL" contains, as elements, concept "WOOD" and concept "GRAPHITE". A set type database which allows the construction of concepts on the basis of a set will be explained below.

Definitions of Concept, Element Set and Element Concept!

First, some terms to be used hereinafter will be defined bellow, and various rules will be also

                                      TABLE 2                                      __________________________________________________________________________     Record                                                                              Concept                                                                            Element Field                                                         No.  Field                                                                              A    B     C    D     E                                               __________________________________________________________________________     1    desk                                                                               wood office                                                                               furniture                                                                supplies                                                         2    pencil                                                                             wood graphite                                                                             office                                                                              writing                                                                              cylindri-                                                           supplies                                                                            tools cal form                                        3    wood                                                                               insulator                                                                           combusti-                                                                            plant                                                                               specific                                                            bility     gravity of                                                                     1 or less                                             4    graphite                                                                           conducti-                                                                           softness                                                                             black                                                               bility     color                                                      5    mica                                                                               insulator                                                             6    brush of                                                                           graphite                                                                   motor                                                                     __________________________________________________________________________

explained below. To begin with, concept "A" will be defined/expressed as follows.

Concept Name A {Element Concept Name X, Element Concept Name Y. Element Concept Name Z, . . . } in which "Concept Name A" is name of concept "A", and Element Concept Names X, Y, Z, . . . are names of concepts which are elements constituting concept "A". {Element Concept Name X, Element Concept Name Y, Element Concept Name Z, . . . } will be called an element set. On the other hand, there is a concept having no element concept name. A concept of this type means that an element set is an empty set. Element concept name is constituted of a concept having the same concept name. This concept will be called an element concept.

For example, concept "DESK" can be expressed as

DESK {WOOD, OFFICE SUPPLIES, FURNITURE} in which "DESK" is a concept name, and "WOOD", "OFFICE SUPPLIES" and "FURNITURE" are element concept names. Further, {WOOD, OFFICE SUPPLIES, FURNITURE} is an element set. Further, element concept names "WOOD", "OFFICE SUPPLIES" and "FURNITURE" are constituted of concepts "WOOD", "OFFICE SUPPLIES" and "FURNITURE" having the same concept names "WOOD", "OFFICE SUPPLIES" and "FURNITURE". Concepts "WOOD", "OFFICE SUPPLIES" and "FURNITURE" are elements of concept "DESK". Further, concept "WOOD" can be also expressed as follows.

WOOD {INSULATOR, COMBUSTIBILITY, PLANT, SPECIFIC GRAVITY OF 1 OR LESS}

On the other hand, concept "OFFICE SUPPLIES" and concept "FURNITURE" are concepts having no element concept name. That is, its element set is an empty set. These concepts can be therefore expressed as follows.

OFFICE SUPPLIES { }

FURNITURE { }

Definitions of Parent Concept and Parent Set! When concept "a" is an element concept of concept "A", concept "A" will be called a parent concept of concept "a", and expressed as follows.

A _(e) a

A set consisting of all of parent concepts of concept "a" will be called a parent concept set of concept "a".

For example, concept "WOOD" is an element concept of concept "DESK", and concept "DESK" is a parent concept of concept "WOOD". Further, concept "WOOD" is an element concept of concept "PENCIL", and concept "PENCIL" is a parent concept of concept "WOOD". Further, a set consisting of all of parent concepts (concept "DESK" and concept "PENCIL") of concept "WOOD" is a parent concept set of concept "WOOD". The relationship among concept "WOOD", concept "DESK" and concept "PENCIL" are expressed as follows.

concept "WOOD" ε_(e) concept "DESK"

concept "WOOD" ε_(e) concept "PENCIL"

Definitions of Indirect Parent Concept and Indirect Element Concept!

When concept "A" is an element concept of concept "B" (B _(e) A) and when concept "B" is an element of concept "C" concept (C _(e) B), concept "C" is called an indirect parent concept of concept "A", and this relationship is expressed as follows. On the other hand, concept "A" is called an indirect element concept of concept "C".

C _(i) A

Or, when B _(e) A and D _(i) B, concept "D" is also an indirect parent concept of concept "A", and this relationship is expressed as D _(i) A. On the other hand, concept "A" is called an indirect element concept of concept "D". Further, when B _(i) A and C _(i) B, concept "C" is an indirect parent concept of concept "A", and this relationship is expressed as C _(i) A. The relationship between concept "INSULATOR" and concept "DESK" can be expressed as follows.

concept "DESK" _(i) concept "INSULATOR"

Concept Level!

For example, concept "Insulator" has no element set. That is, its element set is an empty set.

INSULATOR { }

A concept of which the element set is an empty set as above is called a first level concept, and the name of this first level concept is called a first level concept name. For example, concept "INSULATOR", "COMBUSTIBILITY", "PLANT" and "SPECIFIC GRAVITY OF 1 OR LESS" which are element concepts of concept "WOOD" are first level concepts having no qualities by which to define themselves, i.e., having no internal relativity.

Further, second level concept, third level concept, . . . , n-th level concept are expressed as follows.

second level concept: concept whose element concept consists of first level concept(s).

third level concept: concept whose element concept has a maximum level of 2 and which has at least one second level concept as an element concept.

n-th level concept: concept whose element concept has a maximum level of (n-1) and which has at least one (n-1)th level concept as an element concept.

For example, concept "WOOD", concept "GRAPHITE" and concept "MICA" are second level concepts, and concept "DESK" and concept "PENCIL" are third level concepts.

Further, names of second level concept, third level concept, . . . , n-th level concept are called a second level concept name, a third level concept name, . . . , an n-th level concept name.

Change in Concept Level!

A concept level may change when an element concept is deleted or added. That is, when all of (n-1)th level concepts are deleted from the element set of an n-th level concept, the concept level changes to the concept at a level which is obtained by adding 1 to the maximum level of the element concepts of the element set remaining after the deletion. For example, when element concept "WOOD" is deleted from concept "DESK", concept "DESK" changes from a third level concept to a second level concept. On the other hand, when an n-th level or higher level concept as an element concept is added to an n-th level concept, the concept level changes to a level obtained by adding 1 to the maximum level of the element concepts in a new element set.

While an element set does not change, the level of a parent concept or an indirect parent concept may change if the level of the element concept changes. For example, concept "PLANT" is a first level concept. If a first level concept such as "ORGANISM" or "CONSTITUTION FROM CELLS" is included as an element concept, concept "PLANT" changes to a second level concept. As a result, although element concepts constituting concept "WOOD" do not change at all, concept "WOOD" which is a parent concept of concept "PLANT" changes from a second level concept to a third level concept. Accordingly, concept "DESK" and concept "PENCIL" which are indirect parent concepts of concept "PLANT" change from a third level concepts to a 4th level concepts.

Prohibition of Duplication of Concept Name!

A concept name is an identifier of a concept, and a concept name must not be duplicated. Even if concept "X" and concept "Y" have an identical element concept(s) or an identical element set, concept name "X" and concept name "Y" have to be different.

Construction Rules of Concept!

When concept "a" and concept "A" satisfy the following relationship, concept "a" can be an element concept of concept "A".

Rule (1): concept "a" is not an element concept of concept "A".

Rule (2): concept "a" differs from concept "A".

Rule (3): concept "a" is neither an indirect parent concept of concept "A" nor a parent concept thereof.

Rule (1) is given to avoid a useless operation. Even if a plurality of identical concepts are added to an element set, no change takes place in the concept. Rules (2) and (3) are given for excluding a circulating definition. Rule (2) can exclude, e.g., the circulating definition of

DESK {DESK, WOOD, OFFICE SUPPLIES, FURNITURE}.

Further, when the following concepts and elements are present,

A {B}, B {A}, C {A}

concept "A" is indirectly defined to have a circulating definition if Rule (3) is not given.

Rule (3) may be replaced with the following rule.

Rule (3'): concept "A" is neither an indirect element concept of concept "a" nor an element concept thereof.

Fundamental Procedure!

In the set type database for constructing concepts on the basis of sets, the following four fundamental procedures are allowed.

(1) Formation of a new data string.

(2) Addition of new link-information data to a predetermined area of a data string.

(3) Deletion of link-information data from a predetermined area of a data string.

(4) Removal of a data string.

The data retrieval method and the link-information adding method of the present invention will be explained with reference to specific examples hereinafter. Examples 1 to 3 and Example 14 are concerned with the data retrieval method directed to the first aspect of the present invention. Examples 4 and 15 are concerned with the link-information adding method directed to the first aspect of the present invention. Examples 5 and 6 are concerned with the data retrieval method directed to the second aspect of the present invention. Example 7 is concerned with the link-information adding method directed to the second aspect of the present invention. Example 8 is concerned with the data retrieval method directed to the third aspect of the present invention. Examples 9 and 14 are concerned with data retrieval method directed to the fourth aspect of the present invention. Example 10 is concerned with the link-information adding method directed to the third aspect of the present invention. Example 11 is concerned with the link-information adding method directed to the fourth aspect of the present invention. Example 12 is concerned with the link-information adding method directed to the fifth aspect of the present invention. Example 13 is concerned with the link-information adding method directed to the sixth aspect of the present invention.

EXAMPLE 1

Example 1 is concerned with the data retrieval method directed to the first aspect of the present invention. In Example 1, for a data identification name to be retrieved, a data string corresponding to a parent concept and/or an indirect parent concept is extracted.

FIG. 5A shows the structure of a data string in Example 1. A data string is composed of a data identification name storage area Name! in which a data identification name is stored, a data level storage area Level₋₋ value! in which a data level value is stored, and a parent data storage area Parent!. Further, the data string has an identification number storage area ID! in which an identification number for identifying the data string is stored. The identification number is a number characteristic of an individual data string.

A maximum out of data level values stored in the data strings in the data structure will be simply called the maximum data level value, and a data string whose data level storage area Level₋₋ value! stores the maximum data level value will be called n-th level data string. A data string whose data level storage area Level₋₋ value! stores a value of 1 will be called a first level data string. A data string whose data level storage area Level₋₋ value! stores a value of L (1<L<N) will be called L-th level data string. Further, data identification names stored in the data identification name storage areas of an n-th level data string, an L-th level data string and a first level data string will be called an N-th level data identification name, an L-th level data identification name and a first level data identification name, respectively. A data identification name corresponds to the above-explained concept name.

In the data structure in Example 1, a value of 1, 2 or 3 is stored in the data level storage area Level₋₋ value! of each data string. That is, the data structure in Example 1 is constituted of a plurality of first level data strings, a plurality of second level data strings and a plurality of third level data strings.

An N-th level data identification name is a name of a set consisting of at least one (N-1)th level data identification name, or an N-th level data identification name is a name of a set consisting of one (N-1)th level data identification name and further consisting of at least one L'-th level data identification name (in which L'=1, 2, . . . , N-1). An L-th level data identification name is a name of a set consisting of at least one (L-1)th level data identification name, or an L-th level data identification name is a name of a set consisting of one (L-1)th level data identification name and further consisting of at least one L"-th level data identification name (in which L"=1, 2, . . . , L-1). Each data identification name is stored in the data identification name storage area Name! of each data string.

The parent data storage area Parent! of each data string DS₋₋ 1 stores link-information data about a data string DS₋₋ 2 storing a data identification name which indicates a set including the data identification name stored in the data string DS₋₋ 1. The parent data storage area Parent! is composed of a plurality of parent identification number storage areas Parent₋₋ ID!. Further, the data level value of the data string DS₋₋ 2 corresponding to the link-information data stored in the parent data storage area Parent! of the data string DS₋₋ 1 is greater than the data level value of the data string DS₋₋ 1.

When there is an M'-th level data identification name (M'=M+1, M+2, . . . , N) which indicates a set including an M-th level data identification name (1≦M<M'), the link-information data about the M'-th level data string DS₋₋ 2 storing the M'-th level data identification name is stored in the parent data storage area Parent! of the M-th level data string DS₋₋ 1 which stores the M-th level data identification name. Specifically, the identification number of the M'-th level data string DS₋₋ 2 is stored in the parent data storage area Parent! of the M-th level data string DS₋₋ 1. The identification number of M'-th level data string DS₋₋ 2 stored in the parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the M-th level data string DS₋₋ 1 is link-information data in Example 1.

When the M-th level data string DS₋₋ 1 is taken as standard, the M'-th level data string DS₋₋ 2 corresponds to a parent concept. The data identification name stored in the M'-th level data string DS₋₋ 2 corresponds to the above-explained parent concept name. On the other hand, when the M'-th level data string DS₋₋ 2 is taken as standard, the M-th level data string DS₋₋ 1 corresponds to an element concept. Further, when the data identification name stored in the M'-th level data string DS₋₋ 2 is taken as standard, the data identification name stored in the M-th level data string DS₋₋ 1 corresponds to an element concept name. Further, the data identification name(s) of M'-th level data string(s) DS₋₋ 2 corresponding to the link-information data stored in the parent identification number storage area Parent₋₋ ID! of the parent data storage area in the M-th level data string DS₋₋ 1 corresponds to a parent concept set.

Table 3 shows examples of data identification names corresponding to concept names and data level values thereof, and data identification names corresponding to element concept names and data level values thereof in the data structure in Example 1.

FIG. 5B shows a data string structure of a first level data string indicated by ID number 5 in Table 3. The data identification name in the first level data string is "INSULATOR", and this data identification name is stored in the data identification name storage area Name! of the data string. Further, the data level storage area Level₋₋ value! stores "1" which indicates that the data string is a first level data string.

Further, since there are M'-th level data identification names (in this case M'=2 or 3) (specifically, second level data identification names "WOOD" and "MICA") which indicate a set including the first (=M) level data identification name "INSULATOR", identification numbers 12 and 14 of the M'-th level data strings storing these M'-th level data identification names are stored in the parent identification number storage areas Parent₋₋ ID! of the parent data storage area Parent! in the first level data string indicated

                  TABLE 3                                                          ______________________________________                                              Concept Name Recorded                                                     ID   in Data String       Element Concept Name                                 No.  3rd level                                                                               2nd level                                                                               1st level                                                                               2nd level                                                                             1st level                               ______________________________________                                         1                      office                                                                         supplies                                                2                      furniture                                               3                      writing tools                                           4                      cylindrical                                                                    form                                                    5                      insulator                                               6                      combusti-                                                                      bility                                                  7                      plant                                                   8                      specific                                                                       gravity of 1                                                                   or less                                                 9                      conducti-                                                                      bility                                                  10                     softness                                                11                     black color                                             12            wood                     insulator                                                                      combusti-                                                                      bility                                                                         plant                                                                          specific                                                                       gravity of                                                                     1 or 1ess                               13            graphite                 conducti-                                                                      bility                                                                         softness                                                                       black color                             14            mica                     insulator                               15   desk                       wood                                                                                  office                                                                         supplies                                                                       furniture                               16   pencil                     wood                                                                           graphite                                                                              office                                                                         supplies                                                                       writing                                                                        tools                                                                          cylindrical                                                                    form                                    17   brush of                   graphite                                            motor                                                                     ______________________________________                                    

by ID number 5, as link-information data. ID numbers 1 to 4 and 6 to 11 which are first level data strings also have the same structure. Some M-th level data strings have no M'-th level data identification name which indicates a set including the M-th level data identification name. In this case, nothing is stored in the parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the M-th level data string.

FIG. 6A shows a data string structure of a second (M=2) level data string indicated by ID number 12 in Table 3. The data identification name which is a second level data identification name in the second level data string is "WOOD", and the data identification name is stored in the data identification name storage area Name! of the data string. Further, the data level storage area Level₋₋ value! stores "2" which indicates that the data string is a second level data string.

Further, since there are M'-th level data identification names (in this case M'=3) (specifically, third level data identification names "DESK" and "PENCIL") which indicate a set including the second level data identification name "WOOD", identification numbers 15 and 16 of the M'-th level data strings storing these M'-th level data identification names are stored in the parent identification number storage areas Parent₋₋ ID! of the parent data storage area Parent! in the second level data string indicated by ID number 12, as link-information data.

ID numbers 13 and 14 which are second level data strings have the same structure.

FIG. 6B shows a data string structure of a third (=N) level data string indicated by ID number 15 in Table 3. The data identification name in this third level data string is "DESK", and the data identification name is stored in data identification name storage area Name! of the data string. Further, the data level storage area Level₋₋ value! stores "3" which indicates that the data string is a third level data string. In Example 1, the maximum data level value (N) is 3, and therefore, nothing is stored in the parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the third level data string. ID numbers 16 and 17 which are third level data strings also have the same structure.

FIGS. 7A and 7B show data string structures of a third level data string and a second level data string indicated by ID numbers 16 and 14, respectively.

For excluding a circulating definition, the parent data storage area Parent! of the data string DS₋₋ 1 does not contain any link-information data (e.g., identification number) about the data string DS₋₋ 1 itself. Further, the link-information data stored in the parent data storage area Parent! of the data string DS₋₋ 1 differ from one another. These correspond to Rules (1) and (2) explained in "Construction Rule of Concept".

Further, when data strings are consecutively traced on the basis of link-information data stored in parent data storage areas of data strings, with arbitrary link-information data stored in the parent data storage area of the data string DS₋₋ 1 as a starting point, until the parent data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the parent data storage areas of the traced data strings. This corresponds to Rule (3) in the above-explained "Construction Rule of Concept".

For example, if it is assumed that ID number 12 which is link-information data stored in the parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! of the first level data string DS₋₋ 1 indicated by ID number 5 is arbitrary link-information data, data strings are consecutively traced on the basis of the link-information data stored in the parent data storage areas of the data strings with the above link-information data (ID number 12) as a starting point. That is, the operation reaches the data string of ID number 15 on the basis of ID number 15 which is link-information data stored in the parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the data string of ID number 12. The parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the data string of ID number 15 is empty. Therefore, the operation then reaches the data string of ID number 16 on the basis of ID number 16 which is link-information data stored in the next parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the data string of ID number 12. The parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the data string of ID number 16 is empty. Therefore, link-information data stored in the next parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the data string of ID number 12 is traced. This parent identification number storage area Parent₋₋ ID! is empty. In this operation, ID number 5 which is the link-information data about the data string DS₋₋ 1 is included in none of the parent data storage areas of the traced data strings (data strings of ID numbers 12, 15 and 16).

When the first level data string indicated by ID number 5 is taken as standard, the second level data string of ID number 12 corresponds to a parent concept, and further, the third level data string of ID number 15 corresponds to an indirect parent concept. On the other hand, when the third level data string indicated by ID number 15 is taken as standard, the second level data string of ID number 12 corresponds to an element concept, and further, the first level data string of ID number 5 corresponds to an indirect parent concept.

FIG. 34 schematically shows an apparatus suitable for working the data retrieval method or the link-information adding method of the present invention. The apparatus is constituted of a processing unit, an input unit 12, a display unit 16, a main storage device 14 and an external storage device 18 such as a hard disc drive. The processing unit contains, for example, a microprocessor unit 10 (to be abbreviated as MPU 10 hereinafter). The input unit 12 contains, for example, a pointing device (mouse) and a keyboard. The display unit 16 contains a cathode ray tube (CRT) and displays various data. The main storage device 14 contains, for example, a random access memory (RAM) and stores programs and various data to be processed by MPU 10 and data strings. The external storage device 18 stores a data structure which is the object of the data retrieval method or the link-information adding method of the present invention. The data structure may have any file form.

In the data retrieval method in Example 1, first, a data identification name corresponding to data to be retrieved is inputted. Then, a data string is extracted on the basis of link-information data stored in the parent data storage area of the data string (to be sometimes called "inputted data string") whose data identification name storage area stores the inputted data identification name. Further, a data string is extracted on the basis of link-information data stored in the parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty. Then, the extracted data strings are outputted. The retrieval pattern of the data retrieval method in Example 1 is the first retrieving pattern shown in FIGS. 1A and 1B.

The data retrieval method in Example 1 will be explained with reference to flow charts of FIG. 8 and FIG. 9 hereinafter.

As shown in FIG. 8, a letter string "INSULATOR" as an data identification name to be retrieved is inputted first, for example, from the input unit 12 containing, e.g., a keyboard (STEP-S10). MPU 10 reads the inputted letter string "INSULATOR" and stores it in a variable storage area (not shown) of the main storage device 14. Then, MPU 10 accesses the data structure stored in the external storage device 18, extracts (reads out) the data string having the data identification name which is stored in the data identification name storage area Name! and is in agreement with the inputted letter string (inputted data string, or data string of ID number 5 in Example 1) from the data structure (STEP-S11) and stores the content of the inputted data string in the variable storage area of the main storage device 14. When MPU 10 fails in reading out the data string from the data structure, the retrieval operation comes to an end (STEP-S12).

Then MPU 10 checks the parent identification number storage area of parent data storage area of the inputted data string stored in the variable storage area of the main storage device 14, and when the parent identification number storage area is empty, MPU 10 terminates the retrieval procedure (STEP-S13). When the parent identification number storage area is not empty, MPU 10 arranges a dynamic array D(0) in the variable storage area and initializes the dynamic array D(0) (STEP-S14). In the dynamic array D, ID number of a data string is stored. Then, ID number of the inputted data string is stored in the dynamic array D(0) (STEP-S15).

Then, data strings are extracted on the basis of the link-information data stored in the parent data storage area of the inputted data string, and data strings are further extracted on the basis of the link-information data stored in the parent data storage areas of the extracted data strings until the parent data storage area of the extracted data string is empty.

Specifically, the retrieving process 1 shown in FIG. 9 is executed (STEP-S16). In the retrieving process 1, the variable i is set at 0 (STEP-S20).

Then, MPU 10 reads the data string corresponding to ID number stored in the dynamic array D(i) from the data structure and stores it in variable X (STEP-S21). The variable X can be structurally the same as the data string. Then, MPU 10 checks the parent identification number storage area Parent₋₋ ID₋₋ X! of the parent data storage area Parent₋₋ X! in the variable X, and when the parent identification number storage area Parent₋₋ ID₋₋ X! is empty, the operation jumps to STEP-S28 (STEP-S22). When the parent identification number storage area Parent₋₋ ID₋₋ X! is not empty, MPU 10 stores ID number (stored in the head parent identification number storage area Parent₋₋ ID₋₋ X!) in variable PID (STEP-S23).

Thereafter, MPU 10 checks whether ID number stored in the variable PID is present in the dynamic array D (STEP-S24), and when it is present, MPU 10 jumps to STEP-S26. On the other hand, when it is not present, MPU 10 adds ID number stored in the variable PID to the end of the dynamic array D (STEP-S25). Then, MPU 10 checks the next parent identification number storage area Parent₋₋ ID₋₋ X! in the parent data storage area Parent₋₋ X! in the variable X, and when the parent identification number storage area Parent₋₋ ID₋₋ X! is empty, the operation jumps to STEP-S28 (STEP-S26). When the parent identification number storage area Parent₋₋ ID₋₋ X! is not empty, MPU 10 stores ID number (stored in the parent identification number storage area Parent₋₋ ID₋₋ X!) in the variable PID (STEP-S27) and then returns to STEP-S24.

In STEP-S28, the value of the variable i is incremented by 1 (STEP-S28), and MPU 10 checks whether ID number is stored in the dynamic array D(i), i.e., whether the dynamic array D(i) is a tail end (EOF). When ID number is stored in the dynamic array D(i), MPU 10 returns to STEP-S21. When no ID number is stored in the dynamic array D(i), MPU 10 terminates the retrieving process 1 (STEP-S29).

Then, MPU 10 reads the data string corresponding to ID number stored in the dynamic array D(i) from the data structure, and displays the data identification name stored in the data identification name storage area of the above data string and the data level value stored in the data level storage area, for example, on the display unit 16 (STEP-S17). The data identification name to be retrieved may be displayed, or no data identification name to be retrieved may be displayed. The retrieval operation is so-finished.

When "INSULATOR" is retrieved, ID numbers are stored in the dynamic array D(i) in the following order.

                  TABLE 4                                                          ______________________________________                                                D(0)       ID number = 5                                                       D(1)       ID number = 12                                                      D(2)       ID number = 14                                                      D(3)       ID number = 15                                                      D(4)       ID number = 16                                               ______________________________________                                    

As explained above, when "INSULATOR" is inputted as a data identification name to be retrieved, not only "WOOD" and "MICA" which are second level data strings storing the second level data identification name which indicates the set containing "INSULATOR" are extracted, but also "DESK" and "PENCIL" which are third level data strings storing the third level data identification name which indicates the set including "WOOD" can be extracted. That is, even if the element of "INSULATOR" is not included in "DESK" and "PENCIL" which are third level concepts, it can be led out that "DESK" and "PENCIL" includes concept "INSULATOR".

When the "INSULATOR" which is a first level concept is taken as standard in the above example, "WOOD" and "MICA" which are second level concepts correspond to parent concepts, and "DESK" and "PENCIL" which are third level concepts correspond to indirect parent concepts. Table 5 shows the retrieval results. For a reference purpose, parent concept or indirect parent concept is shown after the data level value.

                  TABLE 5                                                          ______________________________________                                         Data identification name                                                                      Data level   Classification                                     of extracted data string                                                                      value        of concept                                         ______________________________________                                         WOOD           2            parent concept                                     MICA           2            parent concept                                     DESK           3            indirect parent                                                                concept                                            PENCIL         3            indirect parent                                                                concept                                            ______________________________________                                    

In Example 1, the first level data identification name is an object to be retrieved, while a second level data identification name to a (N-1)th level data identification name can be used an object to be retrieved depending upon the value of N. Further, extracted data strings may be outputted at the time when ID number stored in the variable PID is added to the end of the dynamic array D in STEP-S25.

EXAMPLE 2

Example 2 is a variant of Example 1. In Example 1, the retrieving pattern in the data retrieval method is the first retrieving pattern shown in FIGS. 1A and 1B. In Example 2, the retrieving pattern in the data retrieval method is the second retrieving pattern shown in FIG. 2. The data retrieval method in Example 2 will be explained with reference to flow charts of FIGS. 10 and 11 hereinafter.

As shown in FIG. 10, first, a letter string "INSULATOR" as a data identification name corresponding to data to be retrieved is inputted from the input unit 12 containing, e.g., a keyboard (STEP-S30). MPU 10 reads inputted letter string "INSULATOR", and stores it in the variable storage area of the main storage device 14. Then, MPU 10 accesses the data structure stored in the external storage device 18, extracts (reads out) the data string having the data identification name which is stored in its data identification name storage area Name! and is in agreement with the inputted letter string (inputted data string, data string of ID number 5 in Example 2) from the data structure (STEP-S31), and stores the content of the inputted data string in a variable Y₁, of the main storage unit 14. The variable Y₁, Y₂, . . . can be structurally the same as that of the data string. When MPU 10 fails in reading out the data string from the data structure, the retrieval procedure is terminated (STEP-S32).

Then, MPU 10 reads the parent identification number storage area Parent₋₋ ID₋₋ Y! of the parent data storage area Parent₋₋ Y! of the inputted data string stored in the variable Y₁ in the main storage device 14 (STEP-S33), and when the parent identification number storage area Parent₋₋ ID₋₋ Y! is empty, the retrieval procedure is terminated (STEP-S34). In Example 2, as shown in FIG. 5B, ID number 12 as link-information data is stored in the head parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the data string of ID number 5, and the retrieving process 2 is executed (STEP-S35).

In the retrieving process 2, a routine shown in FIG. 11 is mainly executed. For the purpose of explanation of Example 2, FIG. 12 will be referred to hereinafter. In FIG. 12, suffixes to "R" indicate the order of the routine, and encircled numerals indicates ID number of data strings. In the routine, on the basis of ID number 12, MPU 10 accesses the data structure stored in the external storage device 18, extracts (reads out) the data string of ID number 12 from the data structure and stores the content of the data string of ID number 12 in a variable Y₂ of the main storage device 14. And, MPU 10 displays "WOOD" which is a second level data identification name stored in the data identification name storage area Name! of the data string of ID number 12 and "2" which is a data level value stored in the data level storage area Level₋₋ value! on the display unit 16 (R₁).

Then, the routine is repeated. That is, MPU 10 reads, as link-information data, the data stored in the head parent identification number storage area Parent₋₋ ID₋₋ Y! of the parent data storage area Parent₋₋ Y! in the content of the data string of ID number 12 stored in the variable Y₂ of the main storage device 14. In Example 2, as shown in FIG. 6A, ID number 15, as link-information data, is stored in the head parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the data string of ID number 12. On the basis of ID number 15, MPU 10 accesses the data structure stored in the external storage device 18, extracts (reads out) the data string of ID number 15 from the data structure and stores the content of the data string of ID number 15 in a variable Y₃ of the main storage device 14. And, MPU 10 displays "DESK" which is a third level data identification name stored in the data identification name storage area Name! of the data string of ID number 15 and "3" which is a data level value stored in the data level storage area Level₋₋ value! on the display unit 16 (R₂).

Further, MPU 10 reads, as link-information data, the data stored in the head parent identification number storage area Parent₋₋ ID₋₋ Y! of the parent data storage area Parent₋₋ Y! in the content of the data string of ID number 15 stored in the variable Y₃ of the main storage device 14. In Example 2, as shown in FIG. 6B, nothing is stored in the head parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the data string of ID number 15. Therefore, MPU 10 escapes from the routine (R₃), and discards the variable Y₃ in the main storage device 14.

Further, the retrieving process 2 is repeated. That is, MPU 10 reads, as link-information data, the data stored in the next parent identification number storage area Parent₋₋ ID₋₋ Y! of the parent data storage area Parent₋₋ Y! in the content of the data string of ID number 12 stored in the variable Y₂ of the main storage device 14. In Example 2, as shown in FIG. 6A, ID number 16, as link-information data, is stored in the second parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the data string of ID number 12. On the basis of ID number 16, MPU 10 accesses the data structure stored in the external storage device 18, extracts (reads out) the data string of ID number 16 from the data structure and stores the content of the data string of ID number 16 in a variable Y₃ of the main storage device 14. And, MPU 10 displays "PENCIL" which is a third level data identification name stored in the data identification name storage area Name! of the data string of ID number 16 and "3" which is a data level value stored in the data level storage area Level₋₋ value! on the display unit 16 (R₄).

Then, MPU 10 reads, as link-information data, the data stored in the head parent identification number storage area Parent₋₋ ID₋₋ Y! of the parent data storage area Parent₋₋ Y! in the content of the data string of ID number 16 stored in the variable Y₃ of the main storage device 14. In Example 2, as shown in FIG. 7A, nothing is stored in the head parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the data string of ID number 16. Therefore, MPU 10 escapes from the routine (R₅), and discards the variable Y₃ in the main storage device 14.

Then, MPU 10 reads the data stored in the next parent identification number storage area Parent₋₋ ID₋₋ Y! of the parent data storage area Parent₋₋ Y! in the content of the data string of ID number 12 stored in the variable Y₂ of the main storage device 14. In Example 2, as shown in FIG. 6A, nothing is stored in the third parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the data string of ID number 12. Therefore, MPU 10 escapes from the routine (R₆), and discards the variable Y₂ in the main storage device 14.

The retrieving process 2 (STEP-S35) is finished once. Then, as shown in FIG. 10, MPU 10 reads, as link-information data, the data stored in the next parent identification number storage area Parent₋₋ ID₋₋ Y! of the parent data storage area Parent₋₋ Y! in the content of the data string of ID number 5 stored in the variable Y₁ of the main storage device 14 (STEP-S36), and returns to STEP-S34.

In Example 2, as shown in FIG. 5B, ID number 14, as link-information data, is stored in the second parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the data string of ID number 5. On the basis of the link-information data stored in the parent data storage area of the inputted data string, again, a data string is extracted, and on the basis of the link-information data stored in the parent data storage area of the extracted data string, a data string is further extracted until the parent data storage area of the extracted data string is empty.

That is, the retrieving process 2 is again executed (STEP-S35). That is, on the basis of ID number stored in the next parent identification number storage area Parent₋₋ ID₋₋ Y! of the parent data storage area Parent₋₋ Y! in the content of the data string of ID number 5 stored in the variable Y₁ of the main storage device 14, MPU 10 accesses the data structure stored in the external storage device 18, extracts (reads out) the data string of ID number 14 from the data structure and stores the content of the data string of ID number 14 in a variable Y₂ of the main storage device 14. And, MPU 10 displays "MICA" which is a second level data identification name stored in the data identification name storage area Name! of the data string of ID number 14 and "2" which is a data level value stored in the data level storage area Level₋₋ value! on the display unit 16 (R₇).

Then, MPU 10 reads the data stored in the head parent identification number storage area Parent₋₋ ID₋₋ Y! of the parent data storage area Parent₋₋ Y! in the content of the data string of ID number 14 stored in the variable Y₂ of the main storage device 14. In Example 2, as shown in FIG. 7B, nothing is stored in the head parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the data string of ID number 14. Therefore, MPU 10 escapes from the routine (R₈), and discards the variable Y₂ in the main storage device 14.

The retrieving process 2 (STEP-S35) is finished once. Then, MPU 10 reads the data stored in the next parent identification number storage area Parent₋₋ ID₋₋ Y! of the parent data storage area Parent₋₋ Y! in the content of the data string of ID number 5 stored in the variable Y₁ of the main storage device 14 (STEP-S36), and returns to STEP-S34. In Example 2, however, as shown in FIG. 5B, nothing is stored in the third parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the data string of ID number 5. Therefore, MPU 10 terminates all the retrieval operation.

Table 6 shows the retrieval results in Example 2. For a reference purpose, parent concept or indirect parent concept is shown after the data level value.

                  TABLE 6                                                          ______________________________________                                         Data identification name                                                                      Data level   Classification                                     of extracted data string                                                                      value        of concept                                         ______________________________________                                         WOOD           2            parent concept                                     DESK           3            indirect parent                                                                concept                                            PENCIL         3            indirect parent                                                                concept                                            MICA           2            parent concept                                     ______________________________________                                    

EXAMPLE 3

Example 3 is also concerned with the data retrieval method directed to the first aspect of the present invention. In Examples 1 and 2, the number of data identification name to be retrieved was 1, while a plurality of data identification names are retrieved in Example 3. The data retrieval method explained in Example 1 or 2 is executed for data identification names to be retrieved. And, the number of the data identification names to be retrieved with regard to each of the extracted data strings are outputted. The data retrieval method of outputting the number of the data identification names to be retrieved with regard to each of the extracted data strings will be called "a data retrieval method of scrap method" hereinafter.

Example 3 will specifically explained on the basis of the data structure explained in Example 1. The retrieving pattern is the same as the first retrieving pattern in Example 1, while the second retrieving pattern explained in Example 2 may be used. The number of data identification names to be retrieved is 3, i.e., the data identification names to be retrieved are "INSULATOR", "BLACK COLOR" and "OFFICE SUPPLIES". The data level values of data strings storing the data identification names to be retrieved may be the same or different. The data retrieval method in Example 3 will be explained with reference to flow charts of FIGS. 13 and 14 hereinafter.

As shown in FIG. 13, first, letter strings "INSULATOR", "BLACK COLOR" and "OFFICE SUPPLIES" are inputted from the input unit 12 containing, e.g., a keyboard, as data identification names corresponding to data to be retrieved (STEP-S40). MPU 10 reads the letter strings "INSULATOR", "BLACK COLOR" and "OFFICE SUPPLIES" and stores them in the variable storage areas (not shown) in the main storage device 14. Then, MPU 10 substitutes "1" in a variable j, then accesses the data structure stored in the external storage device 18, extracts (reads out) the data string (first inputted data string) having a data identification name (data string of ID number 5 in Example 3) which is stored in its data identification name storage area Name! and is in agreement with the inputted letter string from the data structure, and stores the content of the read-out data string in the variable storage area of the main storage device 14. This procedure is conducted as many times as the number of the inputted data identification names. That is, in Example 3, MPU 10 accesses the data structure stored in the external storage device 18, extracts (reads out) the data string of ID number 11 from the data structure, and stores the content of the read-out data string (second inputted data string) in the variable storage area of the main storage device 14. Further, MPU 10 accesses the data structure stored in the external storage device 18, extracts (reads out) the data string of ID number 1 from the data structure, and stores the content of the read-out data string (third inputted data string) in the variable storage area of the main storage device 14 (STEP-S41). When MPU 10 fails in reading out the data string from the data structure, the retrieval procedure is terminated (STEP-S42). Then, MPU 10 checks the parent identification number storage areas of the parent data storage areas of all the data strings stored in the variable storage area in the main storage device 14, and when all the parent identification number storage areas of data strings are empty, the retrieval procedure is terminated (STEP-S43).

On the other hand, when the parent identification number storage area of any inputted data string is not empty, MPU 10 prepares a dynamic array D(0) in the variable storage area and initializes the dynamic array D(0) (STEP-S44). The dynamic array D stores ID number of the data string. Then, out of data strings stored in the variable storage area in the main storage device 14, MPU 10 stores, in the dynamic array D(0), ID number 5 of the first inputted data string which is a data string storing the first data identification name to be retrieved first (STEP-S45).

Then, a data string is extracted on the basis of the link-information data stored in the parent data storage area of the first inputted data string, and a data string is further extracted on the basis of the link-information data stored in the parent data storage area of the extracted data string until the parent data storage areas of the extracted data string is empty. Specifically, the same retrieving process 1 as that of Example 1 shown in FIG. 9 is executed (STEP-S46).

Then, MPU 10 prepares array D_(j) (=D₁), copies the content of the dynamic array D(i) to the array D_(j) (i) and discards the dynamic array D(i). Then, MPU 10 checks whether a next inputted data string is stored in the variable storage area of the main storage device 14 (STEP-S48). When the next inputted data string is not stored in the variable storage area of the main storage device 14, MPU 10 moves to STEP-S50. Table 7 shows the contents of D₁.

                  TABLE 7                                                          ______________________________________                                                D.sub.1 (0)                                                                               ID number = 5                                                       D.sub.1 (1)                                                                               ID number = 12                                                      D.sub.1 (2)                                                                               ID number = 14                                                      D.sub.1 (3)                                                                               ID number = 15                                                      D.sub.1 (4)                                                                               ID number = 16                                               ______________________________________                                    

When the next inputted data string is stored in the variable storage area of the main storage device 14, MPU 10 increments the variable j by 1 and returns to STEP-S44. That is, MPU 10 again prepares a dynamic array D(0) in the variable storage area and initializes the dynamic array D(0) (STEP-S44). Then, MPU 10 stores ID number 11 of the second inputted data string in the dynamic array D(0) (STEP-S45).

Then, a data string is extracted on the basis of the link-information data stored in the parent data storage area of the second inputted data string, and a data string is further extracted on the basis of the link-information data stored in the parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty. Specifically, the same retrieving process 1 as that of Example 1 is executed (STEP-S46).

Then, MPU 10 prepares array D_(j) (=D₂), copies the content of the dynamic array D(i) to the array D₂ and discards the dynamic array D(i). Table 8 shows the contents of D₂.

                  TABLE 8                                                          ______________________________________                                                D.sub.2 (0)                                                                               ID number = 11                                                      D.sub.2 (1)                                                                               ID number = 13                                                      D.sub.2 (2)                                                                               ID number = 16                                                      D.sub.2 (3)                                                                               ID number = 17                                               ______________________________________                                    

Then, MPU 10 checks whether a next inputted data string is stored in the variable storage area of the main storage device 14 (STEP-S48). In Example 3, the next inputted data string (corresponding to ID number 1) is stored in the variable storage area of the main storage device 14, MPU 10 increments the variable j by 1, returns to STEP-S44, and executes STEP-S45, STEP-S46 and STEP-S47. In STEP-S47, the content of the dynamic array D(i) is copied to D_(j) (=D₃). Table 9 shows the contents of D₃.

                  TABLE 9                                                          ______________________________________                                                D.sub.3 (0)                                                                               ID number = 1                                                       D.sub.3 (1)                                                                               ID number = 15                                                      D.sub.3 (2)                                                                               ID number = 16                                               ______________________________________                                    

Then, MPU 10 checks whether a next inputted data string is stored in the variable storage area of the main storage device 14 (STEP-S48). In Example 3, since no inputted data string is stored in the above variable storage area, MPU 10 moves to STEP-S50.

In STEP-S50 shown in FIG. 14, MPU 10 prepares dynamic array R(0) and initializes it. The dynamic array R contains an ID number storage area ID₋₋ R! and a count area Count₋₋ R!.

Then, MPU 10 substitutes "1" in the variables i and j (STEP-S51) and reads the content (ID number) of the array D_(j) (i) (STEP-S52). MPU 10 checks whether the array D_(j), has data (STEP-S53), and if no data is there, MPU 10 returns to STEP-S58. If data is there, MPU 10 checks all of ID number storage areas ID₋₋ R! of the dynamic array R as to whether the content (ID number) of the array D_(j) (i) is recorded (STEP-S54). If no record is there, MPU 10 adds ID number storage area ID₋₋ R! storing the above ID number and a count area Count₋₋ R! storing "1" to the end of the dynamic array R (STEP-S55). If the record is there, MPU 10 increments the value of the count area Count₋₋ R! of element of the dynamic array R storing the above ID number by 1 (STEP-S56). Then, MPU 10 increments the variable i by 1 (STEP-S57) and returns to STEP-S52.

In STEP-S58, MPU 10 substitutes "1" in the variable i, increments the variable j by 1 and then checks whether the value of the variable j exceeds the number of the inputted data strings (STEP-S59). If the value of the variable j does not exceed the number of the inputted data strings, MPU 10 returns to STEP-S52. If the value of the variable j exceeds the number of the inputted data strings, MPU 10 consecutively reads out the data strings corresponding to ID numbers stored in ID number storage area ID₋₋ R! of the dynamic array R, from the data structure in the main storage device 14. The reading starts in the dynamic array R(1). And, MPU 10 displays the data identification name stored in the data identification name storage areas of the read-out data string and the value (hit number of the inputted data strings) stored in the count area Count₋₋ R! (STEP-S60). Table 10 shows a display example. For a reference purpose, data identification names inputted for the retrieval are given after the hit number of the inputted data strings.

In Example 3, the number of the data identification names to be retrieved is outputted with regard to each of the extracted second level data string and third data string. It can be determined in advance by inputting a data level value through the input unit 12 whether the number of the data identification names to be retrieved is outputted with regard to each of the extracted data strings having the inputted data level value.

In the data retrieval method of the scrap method, the value (hit number of the inputted data strings) stored in the count area Count₋₋ R! of the dynamic array R shows how many of the three data identification names "INSULATOR", "BLACK COLOR" and "OFFICE SUPPLIES" are included in, or related to, the extracted data strings. For example, the value of the count area in the third level data string having "PENCIL" as a data identification name is "3", and

                  TABLE 10                                                         ______________________________________                                         Data                                                                           identification                                                                               Hit number of                                                                               Data identification                                 name of extracted                                                                            inputted data                                                                               name to be                                          data string   strings      retrieved                                           ______________________________________                                         WOOD          1            INSULATOR                                           MICA          1            INSULATOR                                           DESK          2            INSULATOR                                                                      OFFICE SUPPLIES                                     PENCIL        3            INSULATOR                                                                      BLACK COLOR                                                                    OFFICE SUPPLIES                                     GRAPHITE      1            BLACK COLOR                                         BRUSH OF MOTOR                                                                               1            BLACK COLOR                                         ______________________________________                                    

therefore, three data identification names to be retrieved are directly or indirectly included in the third level concept name "PENCIL".

The above "directly included" means that a concept expressed by the data identification name to be retrieved is an element concept of a certain concept. The above "indirectly included" means that a concept expressed by the data identification name to be retrieved is an indirect element concept of a certain concept. Specifically, the first level concept name "OFFICE SUPPLIES" is directly included in the third level concept name "PENCIL". On the other hand, the first level concept names "INSULATOR" and "BLACK COLOR" are indirectly included in the third level concept name "PENCIL".

The above third level concept name "PENCIL" including all of three first level concept names to be retrieved corresponds to a retrieval result obtained by connecting the three first level concept names to be retrieved, by a conventional condition of "AND".

Further, for example, the value (hit number of the inputted data strings) stored in the count area Count₋₋ R! in the third level data string having "DESK" as a data identification name is "2". Therefore, two first level concept names corresponding to two data identification names to be retrieved are directly or indirectly included in the third level concept name "DESK". The value (hit number of the inputted data strings) stored in the count area Count₋₋ R! in the second level data string having "WOOD", "GRAPHITE" and "MICA" as data identification names is "1", and the value (hit number of the inputted data strings) stored in the count area Count₋₋ R! in the third level data string having "BRUSH OF MOTOR" as a data identification name is "1". Therefore, one first level concept name corresponding to one data identification name to be retrieved is directly or indirectly included in the above second level concept name and third level concept name.

That is, the second or third level concept name containing at least one of the three concept names corresponding to the three data identification names to be retrieved corresponds to a retrieval result obtained by connecting the three concept names to be retrieved by a conventional retrieval condition of "OR". Unlike a conventional data retrieval method, however, it is possible to check how many data identification names to be retrieved are related to the extracted second level data string and the extracted third level data string.

In Example 3, the data identification names stored in the first level data string are objects to be retrieved, while, although depending upon the value of level N, the objects to be retrieved may be a combination of data identification names stored in the first level data string to (N-1)th level data string.

EXAMPLE 4

Example 4 is concerned with the link-information adding method directed to the first aspect of the present invention. In Example 4, the data string structure in the data structure and various data stored in data strings are the same as those in Example 1. Prior to the explanation of the link-information adding method in Example 4, the procedure or operation of the formation of a data string as the introduction of a new data string to the data structure will be explained below.

The formation of a new data string in the data structure is preferably conducted by introducing a new first level data string to the data structure. When a new data identification name is inputted through the input unit 12, MPU 10 checks whether the inputted data identification name is already stored in the data identification name storage areas Name! of the data strings in the data structure. If the inputted data identification name is already stored in the data identification name storage area Name! of any data string in the data structure, MPU 10 discontinues the operation. If the above is not the case, MPU 10 forms a data string having a structure shown, e.g., in FIG. 5A in the main storage device 14, gives a new ID number, stores the ID number in the identification number storage area ID!, stores the inputted data identification name in the data identification name storage area Name! and stores "1" in the data level storage area Level₋₋ value!. And, MPU 10 adds the above data string to the data structure in the external storage device 18.

The link-information adding method in Example 4 will be explained with reference to flow charts of FIGS. 15 to 18 hereinafter.

As shown in FIG. 15, a data identification name is inputted through the input unit 12 containing, e.g., a keyboard, and a parent concept name which indicates a set including the data identification name is inputted (STEP-S70). In Example 4, the data identification name is "COMBUSTIBILITY", and the parent concept name is "PLANT". MPU 10 reads the inputted letter strings "COMBUSTIBILITY" and "PLANT", and stores them in the variable storage areas established in the main storage device 14.

MPU 10 checks whether the inputted data identification name is in agreement with the inputted parent concept name (STEP-S71), and if it is in agreement, MPU 10 discontinues the addition of the link-information data since the above-explained Rule (2) is violated.

If the inputted data identification name is not in agreement with the inputted parent concept name, a data string (inputted data string, DS₋₋ I) storing the inputted data identification name is extracted (read out), and a data string DS₋₋ P (to be sometimes referred to as "parent concept data string" hereinafter) storing the data identification name in agreement with the inputted parent concept name is extracted (read out) (STEP-S72). That is, MPU 10 accesses the data structure stored in the external storage device 18, extracts (reads out) the data string DS₋₋ I which has a data identification name stored in its data identification name storage area Name! and is in agreement with the inputted data identification name (data string of ID number 6 in Example 4) from the data structure, and stores the content of the inputted data string in the variable X of the main storage device 14. Further, MPU 10 accesses the data structure stored in the external storage device 18, extracts (reads out) the data string DS₋₋ P having a data identification name which is stored in the data identification name storage area Name! and is in agreement with the inputted concept name (data string of ID number 7 in Example 4) from the data structure, and stores the content of the parent concept data string in the variable Y of the main storage device 14. The variables X and Y can be structurally the same as the data string. If MPU 10 fails in reading out the data string from the data structure, the retrieval procedure is terminated (STEP-S73). When a plurality of parent concept names indicating a set containing the data identification name are inputted, a plurality of variables Y can be established.

MPU 10 checks whether the link-information data about the parent concept data string DS₋₋ P is stored in the parent data storage area of the inputted data string DS₋₋ I. Specifically, MPU 10 reads the parent identification number storage area Parent₋₋ ID₋₋ X! of the parent data storage area Parent₋₋ X! in the content of the inputted data string of ID number 6 stored in the variable X of the main storage device 14, and checks whether ID number 7 is there in the parent identification number storage area Parent₋₋ ID₋₋ X! (STEP-S74). If it is there, the Rule (1) is violated, and the addition of link-information data is discontinued.

If the link-information data about the parent concept data string DS₋₋ P is not stored in the parent data storage area of the inputted data string DS₋₋ I, MPU 10 conducts the check of Rule (3). That is, on the basis of the link-information data stored in the parent data storage area of the parent concept data string DS₋₋ P (ID number 7), a data string is extracted. Further, on the basis of the link-information data stored in the parent data storage area of the extracted data string, a data string is extracted until the parent data storage area of the extracted data string is empty (STEP-S75). Specifically, on the basis of the data of the parent identification number storage area Parent₋₋ ID₋₋ Y! of the parent data storage area Parent₋₋ Y! in the parent concept data string DS₋₋ P stored in the variable Y of the main storage device 14, MPU 10 executes the above-explained first retrieving pattern or second retrieving pattern. In this retrieving step, the data strings of ID number 12, ID number 15 and ID number 16 are extracted.

When any one of the data strings extracted in the above retrieval step is in agreement with the inputted data string DS₋₋ I (ID number 6), Rule (3) is violated and the addition of the link-information data is therefore discontinued (STEP-S76).

When none of the data strings extracted in the above retrieval step is not in agreement with the inputted data string DS₋₋ I, MPU 10 stores the link-information data about the parent concept data string DS₋₋ P in the parent data storage area of the inputted data string DS₋₋ I (ID number 6) (STEP-S77). That is, MPU 10 stores ID number 7 in the new parent identification number storage area Parent₋₋ ID₋₋ X! of the parent data storage area Parent₋₋ X! in the content of the inputted data string DS₋₋ I of ID number 6 stored in the variable X of the main storage device 14.

Then, MPU 10 executes the adjustment of the data level value (STEP-S78). That is, as shown in FIG. 16, MPU 10 compares the data level value of the inputted data string DS₋₋ I (ID number 6) with the data level value of the parent concept data string DS₋₋ P. More specifically, MPU 10 compares the data level value of the data level storage area Level₋₋ X! of the inputted data string DS₋₋ I stored in the variable X of the main storage device 14 with the data level value of the data level storage area Level₋₋ Y! of the parent concept data string DS₋₋ P stored in the variable Y (STEP-S80). And when the value of the data level storage area (Level₋₋ Y)≦the value of the data level storage area Level₋₋ X!, MPU 10 stores a value obtained by adding 1 to the value of the data level storage area Level₋₋ X! in the data level storage area Level₋₋ Y! (STEP-S81). In Example 4, the value of the data level storage area Level₋₋ Y! is equal to the value of the data level storage area Level₋₋ X!, MPU 10 stores "2" in the data level storage area Level₋₋ Y!.

Then, MPU 10 writes the contents of the variables X and Y in the data strings having corresponding ID numbers in the data structure (STEP-S82). As above, the addition of the link-information data for adding new link-information data to the parent data storage area of the data string DS₋₋ I is completed.

The data level value of the data string of ID number 7 changes from "1" to "2", whereby the data level value of the data string (ID number 12 in Example 4) storing the data identification name which indicates a set including the data identification name stored in the data string of ID number 7 changes. Further, the data level value of the data strings (data strings of ID number 15 and ID number 16 in Example 4) storing the data identification names which indicate sets including the data identification name stored in the data string of ID number 12 also changes. Therefore, the readjustment of the data level value (STEP-S79) is required in some cases.

In the above case, on the basis of the link-information data stored in the parent data storage area in the data string DS₋₋ P storing data identification name corresponding to the parent concept name, a data string is extracted, and on the basis of the link-information data stored in the parent data storage area of the extracted data string, a data string is further extracted until the parent data storage area of the extracted data string is empty. If the data level value in the extracted data string (DS-A) is greater than the data level value in the data string (DS-B) extracted on the basis of the link-information data stored in the parent data storage area of the extracted data string (DS-A), a value obtained by adding 1 to the data level value in the extracted data string (DS-A) is stored in the data level storage area of the data string (DB-B).

For the above purpose, MPU 10 prepares a dynamic array F in the variable storage area and initializes the dynamic array F (STEP-S90). The dynamic array F is composed of an ID number storage area ID₋₋ D! and a data level storage area Level₋₋ D!. MPU 10 stores the ID number (stored in the identification number storage area ID₋₋ Y! of the data string stored in the variable Y of the main storage device 14) and the data level value (stored in the data level storage area Level₋₋ Y!) in the ID number storage area ID₋₋ D! and data level storage area Level₋₋ D! of the dynamic array F (STEP-S91). In Example 4, in this STEP-S91, ID number 7 and data level value 2 are stored in the ID number storage area ID₋₋ D! and the data level storage area Level₋₋ D! of the dynamic array F(0). And, the variable i is set at 0 (STEP-S92).

Then, MPU 10 extracts (reads out) the data string corresponding to the ID number stored in the dynamic array F(i) from the data structure, and stores it in the variable X (STEP-S93). The variable X can be structurally the same as the data string. In STEP-S93, the data string corresponding to ID number 7 is extracted (read out) and stored in the variable X.

Then, MPU 10 checks the parent identification number storage area Parent₋₋ ID₋₋ X! of the parent data storage area Parent₋₋ X! in the variable X. If the parent identification number storage area Parent₋₋ ID₋₋ X! is empty, MPU 10 moves to STEP-S101 (STEP-S94). If the parent identification number storage area Parent₋₋ ID₋₋ X! is not empty, MPU 10 reads out the data string corresponding to ID number stored in the head parent identification number storage area Parent₋₋ ID₋₋ X!, from the data structure, and then stores the ID number and the data level value of the read-out data string in a variable P₋₋ ID and a variable P₋₋ Level (STEP-S95). In Example 4, in STEP-S95, the data string corresponding to ID number 12 stored in the head parent identification number storage area Parent₋₋ ID₋₋ X! is extracted (read out) from the data structure, and ID number 12 and data level value "2" of the read-out data string are stored in the variables P₋₋ ID and P₋₋ Level.

When the data level value stored in the variable P₋₋ Level is greater than the data level value stored in the data level storage area Level₋₋ D! of the dynamic array F(i) (STEP-S96), MPU 10 moves to STEP-S99. On the other hand, when the data level value stored in the variable P₋₋ Level is equal to, or smaller than the data level value stored in the data level storage area Level₋₋ D! of the dynamic array F(i) (STEP-S96), the ID number stored in the variable P₋₋ ID and a value obtained by adding 1 to the data level value stored in the data level storage area Level₋₋ D! of the dynamic array (F(i) are added to the ID number storage area ID₋₋ D! and the data level storage area Level₋₋ D! of the end of the dynamic array F (STEP-S97). In Example 4, in STEP-S97, the data level value of "2" stored in the variable P₋₋ Level is equal to the data level value stored in the data level storage area Level₋₋ D! of the dynamic array F(0), ID number 12 stored in the variable P₋₋ ID and "3" which is a value obtained by adding 1 to the data level value stored in the data level storage area Level₋₋ D! of the dynamic array F(i) are added to the ID number storage area ID₋₋ D! and the data level storage area Level₋₋ D! in the end of the dynamic array F. That is, ID number 12 is stored in the ID number storage area ID₋₋ D! of the dynamic array F(1), and the data level value of "3" is stored in the data level storage area Level₋₋ D! of the dynamic array F(1).

Further, MPU 10 writes a value obtained by adding 1 to the data level value (stored in the data level storage area Level₋₋ D! of the dynamic array F(i)) in the data level storage area Level₋₋ value! of the data string, in the data structure, corresponding to the ID number stored in the variable P₋₋ ID (STEP-S98). In Example 4, in STEP-S98, the value "3" obtained by adding 1 to the data level value stored in the data level storage area Level₋₋ D! of the dynamic array F(i) is written in the data level storage area Level₋₋ value! of the data string, in the data structure, corresponding to ID number 12 stored in the variable P₋₋ ID.

Then, MPU 10 checks the next parent identification number storage area Parent₋₋ ID₋₋ X! of the parent data storage area Parent₋₋ X! in the variable X (STEP-S99). If the parent identification number storage area Parent₋₋ ID₋₋ X! is not empty, MPU 10 extracts (reads out) the data string corresponding to the ID number stored in the above next parent identification number storage area Parent₋₋ ID₋₋ X! from the data structure, stores the ID number and data level value of the read-out data string in the variables P₋₋ ID and P₋₋ Level (STEP-S100), and then returns to STEP-S96.

When the above next parent identification number storage area Parent₋₋ ID₋₋ X! is empty, MPU 10 increments the value of i by 1 (STEP-S101) and checks whether data is there in the dynamic array F(i). If data is there in the dynamic array F(i), MPU 10 returns to STEP-S93. If no data is there in dynamic array F(i), the readjustment of the data level value is finished.

In Example 4, the next parent identification number storage area Parent₋₋ ID₋₋ X! of the variable X is empty, and therefore, MPU 10 increments the value of i by 1 (STEP-S101) and checks whether data is there in the dynamic array F(1) (STEP-S102). Since the dynamic array F(1) has data, MPU 10 returns STEP-S93.

Table 11 shows contents of the dynamic array F, obtained before the readjustment of the data level value is finished. Further, Table 12 shows the result of the readjustment of the data level value in the data structure shown in Table 3.

                  TABLE 11                                                         ______________________________________                                         F(i)           P.sub.-- ID                                                                           P.sub.-- Level                                           ______________________________________                                         F(0)           7      2                                                        F(1)           12     3                                                        F(2)           15     4                                                        F(3)           16     4                                                        ______________________________________                                    

In Example 4, one parent concept name which indicates a set including the data identification name is inputted, while a plurality of parent concept names may be inputted for adding link-information data.

EXAMPLE 5

Example 5 relates to the data retrieval method directed to the second aspect of the present invention. In Example 5, for a data identification name to be retrieved, a data string corresponding to an element concept and/or an indirect element concept are extracted.

FIG. 19A shows the data string structure in Example 5. The data string is composed of a data

                                      TABLE 12                                     __________________________________________________________________________     Concept Name Recorded in Data String                                                                   Element Concept Name                                   ID 4th 3rd 2nd 1st      3rd                                                                               2nd 1st                                             No.                                                                               level                                                                              level                                                                              level                                                                              level    level                                                                             level                                                                              level                                           __________________________________________________________________________     1              office supplies                                                 2              furniture                                                       3              writing tools                                                   4              cylindrical form                                                5              insulator                                                       6              combustibility                                                  7          plant               combustibility                                  8              specific gravity of 1                                                          or less                                                         9              conductibility                                                  10             softness                                                        11             black color                                                     12     wood                    insulator                                                                      combustibility                                                             plant                                                                              specific gravity of 1                                                          or less                                         13         graphite            conductibility                                                                 softness                                                                       black color                                     14         mica                insulator                                       15 desk                 wood                                                                                  office supplies                                                                furniture                                       16 pencil               wood                                                                              graphite                                                                           office supplies                                                                writing tools                                                                  cylindrical form                                17     brush of            graphite                                                   motor                                                                   __________________________________________________________________________

identification name area Name! in which a data identification name is stored, a data level storage area Level! in which a data level value is stored, and an element data storage area Element!. The data string further contains an ID number storage area ID! in which an identification number for identifying the data string is stored. The identification number is characteristic of the data string.

In the data structure in Example 5, the data level storage area Level! of each data string stores a value of 1, 2 or 3. That is, the data structure in Example 5 is composed of a plurality of first level data strings, a plurality of second level data strings and a plurality of third level data strings.

The element data storage area Element! of each data string DS₋₋ 1 stores link-information data about a data string DS₋₋ 0 storing a data identification name which is an element of a set indicated by the data identification name stored in the data string DS₋₋ 1. The element data storage area Element! is composed of a plurality of element identification number storage areas Element₋₋ ID!. Further, the data string DS₋₋ 0 corresponding to the link-information data stored in the element data storage area Element! has a smaller data level value than the data string DS₋₋ 1 containing this element data storage area Element! has.

When there is an m'-th level data identification name (m'=1, 2, . . ., N-1) which is an element of a set indicated by an m-th level data identification name (m'<m≦N), the link-information data about the m'-th level data string is stored in the element data storage area Element! of the m-th level data string. Specifically, the identification number of the m'-th level data string DS₋₋ 0 is stored in the element identification number storage area Element₋₋ ID! of the element data storage area Element! in the m-th level data string DS₋₋ 1. The identification number of the m'-th level data string stored in the element identification number storage area Element₋₋ ID! of the element data storage area Element! in the m-th level data string is link-information data in Example 5.

When the m-th level data string is taken as standard, the m'-th level data string corresponds to an element concept. Further, the data identification name stored in the m'-th level data string corresponds to the above-explained element concept name. On the other hand, when the m'-th level data string is taken as standard, the m-th level data string corresponds to a parent concept. Further, the data identification name stored in the m'-th level data string is taken as standard, the data identification name stored in the m-th level data string corresponds to a parent concept name. Further, the data identification name of the m'-th level data string DS₋₋ 0 corresponding to the link-information data stored in the element identification number storage area Element₋₋ ID! of element data storage area Element! in the m-th level data string DS₋₋ 1 corresponds to an element concept set.

In the data structure in Example 5, specifically, the data identification name corresponding to a concept name and the data level value thereof, and the data identification name corresponding to an element concept name and the data level value thereof are the same as those in the data structure shown in Table 3.

FIG. 19B shows a data string structure of a first level data string indicated by ID number 5 in Table 3. The data identification name in the first level data string is "INSULATOR", and this data identification name is stored in a data identification name storage area Name! of the data string. Further, a data level storage area Level₋₋ Value! stores "1" which indicates that the data string is a first level data string.

Further, since the first level data string storing the first level data identification name "INSULATOR" has no element contained in a set indicated by the first level data identification name "INSULATOR", nothing is stored in the element identification number storage area Element₋₋ ID! of the element data storage area Element!. ID numbers 1 to 4 and 6 to 11 which are first level data strings also have similar structures.

FIG. 20A shows a data string structure of a second (=m) level data string indicated by ID number 12 in Table 3. The data identification name as a second level data identification name in the second level data string is "WOOD", and this data identification name is stored in a data identification name storage area Name! of the data string. Further, a data level storage area Level₋₋ Value! stores "2" which indicates that the data string is a second level data string.

Further, the above second level data string storing the data identification name "WOOD" has m'-th level data identification names (m'=1 in this case) which are elements of a set indicated by the data identification name "WOOD" (specifically, the data strings storing the data identification names "INSULATOR", "COMBUSTIBILITY" and "SPECIFIC GRAVITY OF 1 OR LESS"). Therefore, the identification numbers 5, 6, 7 and 8 of the m'-th level data string storing the above m'-th level data identification names are stored, as link-information data, in the element identification number storage areas Element₋₋ ID! of the element data storage area Element! in the second level data string indicated by ID number 12.

ID numbers 13 and 14 which are second level data strings also have similar structures.

FIG. 20B shows a specific data string structure of a third (=N) level data string indicated by ID number 15 in Table 3. The data identification name in the third level data string is "DESK", and this data identification name is stored in a identification name storage area Name! of the data string. Further, a data level storage area Level₋₋ Value! stores "3" which indicates that the data string is a third level data string.

The above third level data string storing the data identification name "DESK" has m'-th level data identification names (m'=1 and 2) which are elements of a set indicated by the data identification name "DESK" (specifically, the data strings storing the data identification names "OFFICE SUPPLIES", "FURNITURE" and "WOOD"). Therefore, identification numbers 1, 2 and 12 of the m'-th level data string storing the above m'-th level data identification name are stored, as link-information data, in the element identification number storage areas Element₋₋ ID! of the element data storage area Element! in the third level data string indicated by ID number 15.

FIGS. 21A and 21B show specific data string structures of the third level data string and the second level data string indicated by ID number 16 and ID number 14 in Table 3.

For excluding a circulating definition, the element data storage area Element! of the data string DS₋₋ 1 does not contain any link-information data (e.g., identification number) about the data string DS₋₋ 1 itself. Further, the link-information data stored in the element data storage area of the data string DS₋₋ 1 differ from one another. These correspond to Rules (2) and (1) of the above "Construction Rule of Concept".

Further, when data strings are consecutively traced on the basis of link-information data stored in the element data storage areas of data strings, with arbitrary link-information data stored in the element data storage area of the data string DS₋₋ 1 as a starting point, until the element data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the element data storage areas of the traced data strings. This corresponds to Rule (3') in the above "Construction Rule of Concept".

For example, when ID number 12 which is the link-information data stored in the element identification number storage area Element₋₋ ID! of the element data storage area Element! in a third level data string DS₋₋ 1 indicated by ID number 15 is supposed to be arbitrary link-information data, data strings are consecutively traced on the basis of the link-information data stored in the element data storage areas of data strings with the above arbitrary link-information data as a starting point. That is, the data string of ID number 5 is reached on the basis of ID number 5 which is the link-information data stored in the element identification number storage area Element₋₋ ID! of the element data storage area Element! in the data string of ID number 12. The element identification number storage area Element₋₋ ID! of the element data storage area Element! in the data string of ID number 5 is empty. Therefore, the data string of ID number 6 is reached on the basis of the link-information data stored in the next element identification number storage area Element₋₋ ID! of the element data storage area Element! in the data string of ID number 12. The element identification number storage area Element₋₋ ID! of the element data storage area Element! in the data string of ID number 6 is empty. This is also the case with ID numbers 7 and 8 which are the link-information data stored in other element identification number storage areas Element₋₋ ID! of element data storage area in the data string of ID number 12. In the above procedures, ID number 15 which is the link-information data about the data string DS₋₋ 1 is included in none of the element data storage areas of the traced data strings (data strings of ID numbers 12, 5, 6, 7 and 8 in the above case).

When the third level data string indicated by ID number 15 is taken as standard, the second level data string of ID number 12 corresponds to an element concept, and the first level data strings of ID numbers 5, 6, 7, and 8 correspond to indirect element concepts. On the other hand, when the first level data string indicated by ID number 5 is taken as standard, the second level data string of ID number 12 corresponds to a parent concept, and the third level data string of ID number 15 corresponds to an indirect parent concept.

In Example 5, a data identification name to be retrieved is first inputted. Then, a data string is extracted on the basis of link-information data stored in the element data storage area of the data string (inputted data string) whose data identification name storage area stores the inputted data identification name. Further, a data string is extracted on the basis of the link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty. The data retrieving pattern in the data retrieval method in Example 5 is the third retrieving pattern shown in FIGS. 3A and 3B.

The data retrieval method in Example 5 will be explained with reference to flow charts of FIGS. 22 and 23 hereinafter.

A letter string "DESK" which is a data identification name corresponding to data to be retrieved is inputted through the input unit 12 containing, e.g., a keyboard (STEP-S110). MPU 10 reads the inputted letter string "DESK" and stores it in the variable storage area (not shown) of the main storage device 14. Then, MPU 10 accesses the data structure stored in the external storage device 18, extracts (reads out) the data string having the data identification name which is stored in the data identification name storage area Name! and is in agreement with the inputted letter string (inputted data string and data string of ID number 15 in Example 5) from the data structure (STEP-S111), and stores the content of the inputted data string in the variable storage area of the main storage device 14. When MPU 10 fails in reading out the data string from the data structure, MPU 10 terminates the retrieval procedure (STEP-S112).

Then, MPU 10 checks the element identification number storage area of the element data storage area of the inputted data string stored in the variable storage area of the main storage device 14, and when the element identification number storage area is empty, MPU 10 terminates the retrieval procedure (STEP-S113). When the element identification number storage area is not empty, MPU 10 prepares a dynamic array D(0) in the variable storage area and initializes the dynamic array D(0) (STEP-S114). The ID number of the data string is stored in the dynamic array D. Then, MPU 10 stores ID number of the inputted data string in the dynamic array D(0) (STEP-S115).

Then, a data string is extracted on the basis of the link-information data stored in the element data storage area of the inputted data string. A data string is further extracted on the basis of the link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty. Specifically, MPU 10 executes the retrieving process 3 shown in FIG. 23. In the retrieving process 3, the variable i is set at 0 (STEP-S120).

Then, MPU 10 extracts (reads out) the data string corresponding to the ID number stored in the dynamic array D(i) from the data structure and stores it in a variable X (STEP-S121). The variable X can be structurally the same as the data string. Then, MPU 10 checks the element identification number storage area Element₋₋ ID₋₋ X! of the element data storage area Element₋₋ ID! in the variable X, and when the element identification number storage area Element₋₋ ID₋₋ X! is empty, MPU 10 returns to STEP-S128 (STEP-S122). When the element identification number storage area Element₋₋ ID₋₋ X! is not empty, MPU 10 stores ID number (stored in the head element identification number storage area Element₋₋ ID₋₋ X!) in a variable EID (STEP-S123).

MPU 10 checks whether the ID number stored in the variable EID is in the dynamic array D (STEP-S124), and if it is there, MPU 10 moves to STEP-S126. On the other hand, if it is not there, MPU 10 adds the ID number stored in the variable EID to the end of the dynamic array D (STEP-S125). Then, MPU 10 checks the next element identification number storage area Element₋₋ ID₋₋ X! of the element data storage area Element₋₋ X! in the variable X, and when the element identification number storage area Element₋₋ ID₋₋ X! is empty, MPU 10 moves to STEP-S128 (STEP-S126). When the element identification number storage area Element₋₋ ID₋₋ X! is not empty, MPU 10 stores ID number (stored in the element identification number storage area Element₋₋ ID₋₋ X!) in the variable EID (STEP-S127) and returns to STEP-S124.

In STEP-S128, MPU 10 increments the value of the variable i by 1 and checks whether ID number is stored in the dynamic array D(i), i.e., whether the dynamic array D(i) has data. When ID number is stored in the dynamic array D(i), MPU 10 returns to STEP-S121. When no ID number is stored, MPU 10 terminates the retrieving process 3.

Then, MPU 10 extracts (reads out) the data string corresponding to the ID number stored in the dynamic array D(i), and displays the data identification name stored in the data identification name storage area of the above data string and the data level value stored in the data level storage area, for example, on the display unit 16 (STEP-S117). The data identification name to be retrieved may be displayed or may not be displayed. The retrieval operation ends after the above.

When "DESK" is retrieved, ID numbers are stored in the dynamic array D(i) in the order shown in the following Table 13.

                  TABLE 13                                                         ______________________________________                                                D(0)       ID number = 15                                                      D(1)       ID number = 1                                                       D(2)       ID number = 2                                                       D(3)       ID number = 12                                                      D(4)       ID number = 5                                                       D(4)       ID number = 6                                                       D(4)       ID number = 7                                                       D(4)       ID number = 8                                                ______________________________________                                    

In Example 5, when "DESK" is inputted as a data identification name to be retrieved, as explained above, "OFFICE SUPPLIES" and "FURNITURE" which are first level data strings and "WOOD" which is a second level data string, as elements of a set indicated by "DESK", are extracted, and moreover, "INSULATOR", "COMBUSTIBILITY", "PLANT" and "SPECIFIC GRAVITY OF 1 OR LESS" which are first level data strings as elements of a set indicated by "WOOD" can be extracted. That is, it can be concluded that "DESK" includes "INSULATOR", "COMBUSTIBILITY", "PLANT" and "SPECIFIC GRAVITY OF 1 OR LESS" as indirect element concepts, without inputting elements such as "INSULATOR", etc. Table 14 shows the retrieval results. For a reference purpose, element concept or indirect element concept is given after the data level values.

                  TABLE 14                                                         ______________________________________                                         Data identification                                                            name of extracted data                                                                       Data level   Classification                                      string        value        of concepts                                         ______________________________________                                         OFFICE SUPPLIES                                                                              1            element concept                                     FURNITURE     1            element concept                                     WOOD          2            element concept                                     INSULATOR     1            indirect element                                                               concept                                             COMBUSTIBILITY                                                                               1            indirect element                                                               concept                                             PLANT         1            indirect element                                                               concept                                             SPECIFIC GRAVITY                                                                             1            indirect element                                    OF 1 OR LESS               concept                                             ______________________________________                                    

In Example 5, the third level data identification name is an object to be retrieved, while a second level data identification name to an N-th level data identification name can be an object to be retrieved. Example 5 has used the third retrieving pattern, while the fourth retrieving pattern may be used in place thereof.

EXAMPLE 6

Example 6 is also concerned with the data retrieval method directed to the second aspect of the present invention. In Example 5, the number of the data identification name to be retrieved is one, while a plurality of data identification names are retrieved in Example 6. The data retrieval method explained in Example 5 is executed with each of data identification names to be retrieved. And, the number of the data identification names to be retrieved with regard to each of the extracted data strings are outputted. That is, Example 6 is concurred with the data retrieval method of the scrap method.

Specifically, Example 6 will be explained using the data structure explained in Example 5. Example 6 also uses the third retrieving pattern as that used in Example 5, while the fourth retrieving pattern may be used. The number of the data identification names to be retrieved is two, that is, "DESK" and "PENCIL" are to be retrieved. The data identification names to be retrieved may have the same data level values or may have different data level values. The data retrieval method in Example 6 will be explained with reference to flow charts of FIGS. 24 and 14.

As shown in FIG. 24, letter strings "DESK" and "PENCIL" are inputted through the input unit 12 containing, e.g., a keyboard (STEP-S130). MPU 10 reads the inputted letter strings "DESK" and "PENCIL" and stores them in the variable storage areas (not shown) of the main storage device 14. Then, MPU 10 substitutes "1" in the variable j, accesses the data structure stored in the external storage device 18, extracts (reads out) the data string having a data identification name which is stored in the data identification name storage area Name! of the data string (data string of ID number 15 in Example 6) and is in agreement with the inputted letter string (first inputted data string) from the data structure, and stores the content of the data string in the variable storage area of the main storage device 14. MPU 10 conducts the above procedure as many times as the number of the inputted data identification names. That is, in Example 6, MPU 10 accesses the data structure stored in the external storage device 18, extracts (reads out) the data string of ID number 16 (second inputted data string) and stores the content of the data string in the variable storage area of the main storage device 14 (STEP-S131). When MPU 10 fails in reading out the data string from the data structure, MPU 10 terminates the retrieval procedure (STEP-S132). Then, MPU 10 checks the element identification number storage areas of the element data storage areas of all of the data strings stored in the variable storage area of the main storage device 14, and when the element identification number storage areas of all the data strings are empty, MPU 10 terminates the retrieval procedure (STEP-S133).

On the other hand, when the element identification number storage area of any data string is not empty, MPU 10 prepares the dynamic array D(0) in a variable storage area and initializes the dynamic array D(0) (STEP-S134). The dynamic array D is to store ID number of the data string. Then, MPU 10 stores ID number 15 of the first inputted data string which is one of the data strings stored in the variable storage area of the main storage device 14 and has the data identification name to be retrieved first, in the dynamic array D(0) (STEP-S135).

Then, on the basis of the link-information data stored in the element data storage area of the first inputted data string, a data string is extracted, and on the basis of the link-information data stored in the element data storage area of the extracted data string, a data string is further extracted until the element data storage area of the extracted data string is empty. Specifically, MPU 10 executes the same retrieving process 3 as that in Example 5 (STEP-S136).

Then, MPU 10 prepares an array D_(j) (=D₁), copies the content of the dynamic array D(i) to the array D_(j) (i) and discards the dynamic array D(i) (STEP-S137). Then, MPU 10 checks whether the next inputted data string is stored in the variable storage area of the main storage device 14 (STEP-S138). When the next inputted data string is not stored in the variable storage area of the main storage device 14, MPU 10 moves to STEP-S50 (see FIG. 14). Table 15 shows the contents of D₁.

                  TABLE 15                                                         ______________________________________                                                D.sub.1 (0)                                                                               ID number = 15                                                      D.sub.1 (1)                                                                               ID number = 1                                                       D.sub.1 (2)                                                                               ID number = 2                                                       D.sub.1 (3)                                                                               ID number = 12                                                      D.sub.1 (4)                                                                               ID number = 5                                                       D.sub.1 (5)                                                                               ID number = 6                                                       D.sub.1 (6)                                                                               ID number = 7                                                       D.sub.1 (7)                                                                               ID number = 8                                                ______________________________________                                    

When the next inputted data string is stored in the variable storage area of the main storage device 14, MPU 10 increments the variable j by 1 and returns to STEP-S134. That is, MPU 10 again prepares a dynamic array D(0) in the variable storage area and initializes the dynamic array D(0) (STEP-S134). Then, MPU 10 stores ID number 16 of the second inputted data string in the dynamic array D(0) (STEP-S135).

Then, on the basis of the link-information data stored in the element data storage area of the second inputted data string, a data string is extracted, and on the basis of the link-information data stored in the element data storage area of the extracted data string, a data string is further extracted until the element data storage area of the extracted data string is empty. Specifically, MPU 10 executes the same retrieving process 3 as that in Example 5 (STEP-S136).

Then, MPU 10 prepares an array D_(j) (=D₂), copies the content of the dynamic array D(i) to the array D₂ and discards the dynamic array D(i) (STEP-S137). Table 16 shows the contents of D₂.

                  TABLE 16                                                         ______________________________________                                                D.sub.2 (0) ID number = 16                                                     D.sub.2 (1) ID number = 1                                                      D.sub.2 (2) ID number = 3                                                      D.sub.2 (3) ID number = 4                                                      D.sub.2 (4) ID number = 12                                                     D.sub.2 (5) ID number = 13                                                     D.sub.2 (6) ID number = 5                                                      D.sub.2 (7) ID number = 6                                                      D.sub.2 (8) ID number = 7                                                      D.sub.2 (9) ID number = 8                                                      D.sub.2 (10)                                                                               ID number = 9                                                      D.sub.2 (11)                                                                               ID number = 10                                                     D.sub.2 (12)                                                                               ID number = 11                                              ______________________________________                                    

Then, MPU 10 checks whether the next inputted data string is stored in the variable storage area of the main storage device 14 (STEP-S138). In Example 6, no next data string is stored in the variable storage area of the main storage device 14, and MPU 10 therefore moves to STEP-S50 (see FIG. 14). Since the procedures in STEP-S50 to STEP-S60 are the same as those in Example 3, the detailed explanation thereof is omitted. Table 17 shows a sample display shown after the procedures in the above steps are completed. For a reference purpose, the inputted data identification names for the retrieval are given after the hit number of the inputted data strings. In Table 17, the hit numbers of the inputted data strings are sorted in the descending order.

                  TABLE 17                                                         ______________________________________                                         Data identification                                                                            Hit number  Date identification                                name of extracted                                                                              of inputted name to be                                         data string     data strings                                                                               retrieved                                          ______________________________________                                         OFFICE SUPPLIES 2           DESK/ PENCIL                                       WOOD            2           DESK/ PENCIL                                       INSULATOR       2           DESK/ PENCIL                                       COMBUSTIBILITY  2           DESK/ PENCIL                                       PLANT           2           DESK/ PENCIL                                       SPECIFIC GRAVITY OF                                                                            2           DESK/ PENCIL                                       1 OR LESS                                                                      FURNITURE       1           DESK                                               WRITING TOOLS   1           PENCIL                                             CYLINDRICAL     1           PENCIL                                             GRAPHITE        1           PENCIL                                             CONDUCTIBILITY  1           PENCIL                                             BLACK COLOR     1           PENCIL                                             SOFTNESS        1           PENCIL                                             ______________________________________                                    

In Example 6, the number of the data identification names to be retrieved is outputted with regard to each of the extracted first level data string and second data string. It can be determined in advance by inputting a data level value through the input unit 12 whether the number of the data identification names to be retrieved is outputted with regard to each of the extracted data strings having the inputted data level value.

In the above scrap method, the value stored in the count area Count₋₋ R! of the dynamic array R (the hit number of the inputted data strings) shows how many inputted data identification names are included or related to each of the extracted data strings. For example, the value (the hit number of the inputted data strings) about the first level data string having "INSULATOR" as a data identification name is "2", which means that two of the inputted data identification names to be retrieved directly or indirectly include the first level concept name "INSULATOR".

The above "directly included" means that a concept expressed by the data identification name to be retrieved is a parent concept of an extracted concept. The above "indirectly included" means that a concept expressed by the data identification name to be retrieved is an indirect parent concept of an extracted concept. Specifically, the third level concept name "DESK" directly includes the first level concept name "OFFICE SUPPLIES". On the other hand, the third level concept names "DESK" indirectly includes the first level concept name "INSULATOR".

The extracted data string directly or indirectly including all of data identification names to be retrieved corresponds to the result of the conventional retrieval using the retrieval condition of "AND" for connecting the data identification names to be retrieved. In Example 6, two data identification names are retrieved. It can be therefore easily found, on the basis of reading the data identification name showing that the hit number of the inputted data strings is "2", which is an element concept (or an indirect element concept) common to the two concepts to be retrieved.

The extracted data string directly or indirectly including at least one of data identification names to be retrieved corresponds to the result of the conventional retrieval using the retrieval condition of "OR" for connecting the data identification names to be retrieved. In Example 6, two data identification names are retrieved. It can be therefore easily found, on the basis of reading the data identification name showing that the hit number of the inputted data strings is "1", which is an element concept (or an indirect element concept) uncommon to the two concepts to be retrieved. As described above, differing from a conventional data retrieval method, the data retrieval method of the present invention makes it possible to easily find how many inputted data identification names are related to each of the extracted data strings.

In Example 6, the data identification names stored in the third level data string are objects to be retrieved, while, although depending upon the value of level N, the objects to be retrieved may be a combination of data identification names stored in the second level data string to the N-th level data string.

EXAMPLE 7

Example 7 is concerned with the link-information adding method directed to the second aspect of the present invention. In Example 7, the data strings in the data structure and the data stored in the data strings are structurally the same as those in Example 5. The link-information adding method in Example 7 will be explained with reference to flow charts of FIGS. 25 and 26 hereinafter.

In Example 7, the data structure of the external storage device 18 additionally contains, as a first level data string, a new data string of ID number 18 having a data identification name of "MOTOR".

As shown in FIG. 25, first, a data identification name is inputted through the input unit 12 containing, e.g., a keyboard, and an element concept name which is an element of a set indicated by the above data identification name is also inputted (STEP-S140). In Example 7, the data identification name is "MOTOR", and the element concept name is "BRUSH OF MOTOR". MPU 10 reads the inputted letter strings "MOTOR" and "BRUSH OF MOTOR" and stores them in the variable storage areas established in the main storage device 14. MPU 10 checks whether the inputted data identification name is in agreement with the element concept name (STEP-S141), and when the agreement is there, the addition of the link-information data is canceled since the above Rule (2) is violated.

When the inputted data identification name is not in agreement with the inputted element concept name, a data string storing the inputted data identification name (inputted data string, DS₋₋ I) is extracted. That is, MPU 10 accesses the data structure stored in the external storage device 18, extracts (reads out) the data string DS₋₋ I having a data identification name which is stored in the data identification name storage area Name! of the data string and which is in agreement with the inputted data identification name (data string of ID number 18 in Example 7) from the data structure (STEP-S142), and stores the content of the inputted data string DS₋₋ I in a variable X of the main storage device 14. MPU 10 also accesses the data structure stored in the external storage device 18, extracts (reads out) the data string DS₋₋ E having a data identification name which is stored in the data identification name storage area Name! and which is in agreement with the inputted element concept name (data string of ID number 17 in Example 7) from the data structure (STEP-S142), and stores the content of the above data string DS₋₋ E (to be sometimes referred to as "element concept data string) in a variable Y of the main storage device 14. The variables X and Y can be structurally the same as that of the data string. When MPU 10 fails in reading out the data string from the data structure, MPU 10 terminates the retrieval procedure (STEP-S143). As explained above, the data string storing the inputted data identification name is extracted, and the data string storing the data identification name in agreement with the inputted element concept name can be extracted. When a plurality of element concept names which are elements of a set indicated by the data identification name are inputted, a plurality of variables Y can be established.

Then, MPU 10 checks whether the link-information data about the element concept data string DS₋₋ E is stored in the element data storage area of the inputted data string DS₋₋ I. Specifically, MPU 10 reads out the element identification number storage area Element₋₋ ID₋₋ X! of the element data storage area Element₋₋ X! in the content of the inputted data string DS₋₋ I of ID number 18 stored in the variable X of the main storage device 14, and checks whether ID number 17 is there in the element identification number storage area Element₋₋ ID₋₋ X! (STEP-S144). If it is there, Rule (1) is violated, and the addition of the link-information data is discontinued.

When the link-information data about the element concept data string DS₋₋ E is not stored in the element data storage area of the inputted data string DS₋₋ I, MPU 10 conducts checks of Rule (3'). That is, a data string is extracted on the basis of the link-information data stored in the element data storage area of the element concept data string DS₋₋ E (ID number 17), and a data string is further extracted on the basis of the link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty (STEP-S145). Specifically, on the basis of the element identification number storage area Element₋₋ ID₋₋ Y! of the element data storage area Element₋₋ Y! in the element concept data string stored in the variable Y of the main storage device 14, MPU 10 executes the already explained third retrieving pattern or fourth retrieving pattern. In the above retrieval step, the data strings of ID numbers 13, 9, 10 and 11 are extracted.

When any one of the data strings extracted in the above retrieval step is in agreement with the inputted data string DS₋₋ I (ID number 18), Rule (3') is violated, and therefore, the addition of the link-information data is discontinued (STEP-S146).

When none of the data strings extracted in the above retrieval step is in agreement with the inputted data string DS₋₋ I, ID number 17 which is the link-information data about the element concept data string DS₋₋ E is stored in the element data storage area of the inputted data string DS₋₋ I (STEP-S147). That is, MPU 10 stores ID number 17 in a new parent identification number storage area Element₋₋ ID₋₋ X! of the element data storage area Element₋₋ X! in the content of the inputted data string of ID number 18 stored in the variable X of the main storage device 14.

Then, MPU 10 executes the adjustment procedure of the data level value in STEP-S148. That is, as shown in FIG. 26, MPU 10 compares the data level value of the inputted data string DS₋₋ I (ID number 18) with the data level value of the element concept data string DS₋₋ E. More specifically, MPU 10 compares the value of the data level storage area Level₋₋ X! of the inputted data string stored in the variable X of the main storage device 14 with the value of the data level storage area Level₋₋ Y! of the element concept data string stored in the variable Y (STEP-S150). If the value of the data level storage area Level₋₋ X!≦the value of the data level storage area Level₋₋ Y!, MPU 10 stores a value obtained by adding 1 to the value of the data level storage area Level₋₋ Y! in the data level storage area Level₋₋ X! (STEP-S151). Since the value of data level storage area Level₋₋ X!(=1)<the value of data level storage area Level₋₋ Y!(=2) in Example 7, MPU 10 stores "3" in the data level storage area Level₋₋ X!.

Then, MPU 10 writes the contents of the variables X and Y in the data strings of the corresponding ID numbers in the data structure (STEP-S152). The link-information addition for adding new link-information data to the element data storage area of the data string is so completed.

The change of the data level value of the data string of ID number 18 from "1" to "3" also causes a change in the data level value of the data string storing the data identification name which indicates a set including the data identification name stored in the data string of ID number 18. It is therefore sometimes required to readjust the data level value (STEP-S149), although there is no such data string in Example 7.

In the above case, there are extracted all of data strings having a greater data level value than the data level value which is not yet adjusted in the inputted data string DS₋₋ I. With regard to the extracted data strings (called starting data strings), each data string is extracted on the basis of the link-information data stored in the element data storage area of the data string according to the third retrieving pattern or the fourth retrieving pattern, and the data strings are further extracted on the basis of the link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty or until the link-information data about the inputted data string DS₋₋ I is found in the element data storage area of the extracted data string. And, if the link-information data about the inputted data string DS₋₋ I is there in the extracted data string, the starting data strings and a series of the data string extracted from the starting data strings are stored. On the other hand, if the link-information data about the inputted data string DS₋₋ I is there in the extracted data string, the above starting data strings are discarded.

Then, the data level values of the starting data strings and a series of the data strings extracted from the above starting data strings are readjusted on the basis of the adjusted data level value of the inputted data string DS₋₋ I. That is, if the data level value of a data string (DS-C) is equal to, or smaller than, the maximum value of the level values of the data extracted strings (DS-D) on the basis of the link-information data stored in the element data storage area of the data string (DS-C), a value obtained by adding 1 to the maximum value of the level values of the extracted data strings (DS-D) is stored in the data level value of the data string (DS-c). The above procedure can be conducted on the basis of the starting data string in the order of from the last data string to the first data string in a series of the extracted data strings, further, up to the starting data string.

The number of the inputted element concept name which is an element of a set indicated by the data identification name is one, while a plurality of element concept names can be inputted for adding link-information data.

EXAMPLE 8

Example 8 is concerned with the data retrieval method directed to the third aspect of the present invention. In Example 8, with regard to a data identification name to be retrieved, there is extracted at least one of a data string corresponding to a parent concept, a data string corresponding to an indirect parent concept, a data string corresponding to an element concept and a data string corresponding to an indirect element concept. The data structure in Example 8 is as shown in Table 12.

FIG. 27 shows the structure of a data string having each level. The data string in Example 8 differs from the data string in Examples 1 and 5 in that the data string in Example 8 has a parent data storage area Parent! and an element data storage area Element!. That is, the data string in Example 8 is composed of an identification number storage area ID!, a data identification name storage area Name!, a data level storage area Level!, a parent data storage area Parent! and an element data storage area Element!. The parent data storage area Parent! is composed of a plurality of parent identification number storage areas Parent₋₋ ID!, and the element data storage area Element! is composed of a plurality of element identification number storage areas Element₋₋ ID!. In Example 8, N=4.

The parent data storage area Parent! of a data string DS₋₋ 1 contains link-information data about a data string DS₋₋ 2 which indicates a set including the data identification name stored in the data string DS₋₋ 1. Further, the data string DS₋₋ 2 corresponding to the link-information data stored in the parent data storage area Parent! of the data string DS₋₋ 1 has a greater data level value than the data string DS₋₋ 1 including the parent data storage area Parent! has.

When there is an M'-th level data identification name (M'=M+1, M+2, . . . , N) which indicates a set including an M-th level data identification name (1≦M<M'), the link-information data about the m'-th level data string DS₋₋ 2 is stored in the parent data storage area Parent! of the M-th level data string DS₋₋ 1. Specifically, the identification number of the M'-th level data string DS₋₋ 2 is stored in the parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the m-th level data string DS₋₋ 1, as link-information data in Example 8.

For excluding a circulating definition as explained in Example 1, the parent data storage area Parent! of the data string DS₋₋ 1 does not contain any link-information data (e.g., identification number) about the data string DS₋₋ 1 itself. Further, the link-information data stored in the parent data storage areas of the data string DS₋₋ 1 differ from one another. These points correspond to Rules (1) and (2) in the already explained "Construction Rule of Concept".

Further, when data strings are consecutively traced on the basis of the link-information data stored in the parent data storage areas of a data strings, with an arbitrary link-information data in the parent data storage area of the data string DS₋₋ 1 as a starting point, until the parent data storage area of the any traced data string is empty, the link-information data about the data string DS₋₋ 1 is contained in none of the parent data storage areas of the traced data strings. This point corresponds to Rule (3) in the already explained "Construction Rule of Concept".

The element data storage area Element! of each data string DS₋₋ 1 stores link-information data about a data string DS₋₋ 0 storing the data identification name which is an element of a set indicated by the data identification name stored in the data string DS₋₋ 1. Further, the data string DS₋₋ 0 corresponding to the link-information data stored in the element data storage area Element! has a smaller data level value than the data string DS₋₋ 1 containing the element data storage area Element! has.

When there is an m'-th level data identification name (m'=1, 2, . . . , N-1) which indicates an element of a set indicated by an m-th level data identification name (m'<m≦N), the link-information data about the m'-th level data string DS₋₋ 0 is stored in the element data storage area Element! of the m-th level data string DS₋₋ 1. Specifically, the identification number of the m'-th level data string DS₋₋ 0 is stored in the element identification number storage area Element₋₋ ID! of the element data storage area Element! in the m-th level data string DS₋₋ 1, as link-information data in Example 8.

For excluding a circulating definition as explained in Example 5, the link-information data (e.g., identification number) about the data string DS₋₋ 1 itself is not contained in the element data storage area Element! of the data string DS₋₋ 1. Moreover, the link-information data stored in the element data storage area of the data string DS₋₋ 1 differ from one another. These points correspond to Rules (1) and (2) of the already explained "Construction Rule of Concept".

Further, when data strings are consecutively traced on the basis of the link-information data stored in the element data storage areas of the data strings, with an arbitrary link-information data stored in the element data storage area of the data string DS₋₋ 1 as a starting point, until the element data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is contained in none of the element data storage areas of the traced data strings. This point corresponds to Rule (3') of the already explained "Construction Rule of Concept".

Example 8 will be explained with reference to the data structure shown in Table 12.

FIG. 28 shows a data string structure of a first level data string indicated by ID number 5 in Table 12. The first level data identification name in the above first level data string is "INSULATOR", and the data identification name is stored in the data identification name storage area Name! of the data string. Further, the data level storage area Level! stores "1" which indicates that the data string is a first level data string.

Further, since there are M'-th level data identification names (M'=2 or 3 in Example 8) which indicate a set including the M-th (=1) level data identification name "INSULATOR" (specifically, second and third level data identification names "WOOD" and "MICA"), the link-information data about the identification numbers 12 and 14 of the M'-th level data strings storing the above M'-th level data identification names (corresponding to link-information data about a parent concept) are stored in the parent identification number storage areas Parent₋₋ ID! of the parent data storage area Parent! in the first level data string indicated by ID number 5. Since the data string indicated by ID number 5 is a first level data string, nothing is stored in the element identification number storage area Element₋₋ ID! of its element data storage area Element!. ID numbers 1 to 4 and 6 to 11 which are first level data strings also have the same structure. Some M-th level data strings have no M'-th level data identification name indicating a set which includes the M-th level data identification name. In this case, nothing is stored in the parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the M-th level data string.

FIG. 29 shows a data string structure of a third (=M) level data string indicated by ID number 12 in Table 12. The third level data identification name in the above third level data string is "WOOD", and this data identification name is stored in the data identification name storage area Name! of the data string. Further, the data level storage area Level! stores "3" which indicates that the data string is a third level data string.

Further, the above third level data string storing the third level data identification name "WOOD" has the M'-th level data identification name (M'=4 in Example 8) indicating a set which includes the above third level data identification name (specifically, 4th level data identification names "DESK" and "PENCIL"), the ID numbers 15 and 16 of the M'-th level data strings storing these M'-th level data identification names (corresponding to link-information data about a parent concept) are stored in the parent identification number storage areas Parent₋₋ ID! of the parent data storage area Parent! in the third level data string indicated by ID number 12.

In the third level data string storing the third level data identification name, further, the link-information data about the first and second level data strings storing the first and second (=m') level data identification names as elements of a set indicated by the third level data identification name is stored in the element data storage area Element! of the data string. Specifically, identification numbers 5, 6 and 8 of the first level data string storing the first level data identification name and identification number 7 of the second level data string storing the second level data identification name (corresponding to link-information data about an element concept) are stored in the element identification number storage areas Element₋₋ ID! of the element data storage area Element! in the third level data string indicated by ID number 12.

ID numbers 13, 14 and 17 which are second and third level data strings also have similar structures.

FIG. 30 shows a data string structure of a 4-th level data string indicated by ID number 15 in Table 12. The above 4-th level data identification name is "DESK", and the data identification name is stored in the data identification name storage area Name! of the data string. Further, the data level storage area Level! stores "4" which indicates that the data string is a 4th level data string.

In the 4th level data string storing the 4th (=N) level data identification name, the link-information data about the third level data string storing the third (=N-1) level data identification name as an element of a set indicated by the 4th level data identification name is stored in the element data storage area Element!. Further, the link-information data about an L'-th level data string storing an L'-th level data identification name (L'=1, 2, . . . , N-1, and L'=1, 2 in the data string of ID number 15) as an element of a set indicated by the 4th level data identification name is stored in the element data storage area Element!. Specifically, identification number 12 of the third level data string storing the third level data identification name (corresponding to link-information data about an element concept) and identification number 1 and 2 of the first level data string storing the first level data identification name (corresponding to link-information data about an element concept) are stored in the element identification number storage areas Element₋₋ ID! of the element data storage area Element! in the 4th level data string indicated by ID number 15.

ID number 16 which is a 4th level data string also has a similar structure. Since the data string has a maximum level of 4 in Example 8, nothing is stored in the parent identification number storage area Parent₋₋ ID! of the parent data storage area Parent! in the 4th level data string.

FIGS. 31 and 32 show data string structures of the second level data string and the 4th level data string indicated by ID numbers 14 and 16 in Table 12.

In the data retrieval method in Example 8, first a data identification name to be retrieved is inputted. Then, a data string is extracted on the basis of the link-information data stored in the parent data storage area of the data string whose data identification name storage area stores the inputted data identification name, and a data string is further extracted on the basis of the link-information data stored in the parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty. The above data retrieval can be conducted by means of the first retrieving pattern shown in FIGS. 1A and 1B and explained in Example 1 or the second retrieving pattern shown in FIG. 2 and explained in Example 2. A data string is also extracted on the basis of the link-information data stored in the element data storage area of the data string whose data identification name storage area stores the inputted data identification name, and a data string is further extracted on the basis of the link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty. The above data retrieval can be conducted by means of the third retrieving pattern shown in FIGS. 3A and 3B and explained in Example 5 or the fourth retrieving pattern shown in FIG. 4. Then, the extracted data strings are outputted. The data retrieval method can be the same as those in Examples 1, 2 and 5 and its detailed explanation is therefore omitted.

For example, when the data to be retrieved is "WOOD", results shown in Table 18 can be obtained.

                  TABLE 18                                                         ______________________________________                                         Data identification                                                                           Data                                                            name of extracted data                                                                        level       Classification of                                   string         value       concept                                             ______________________________________                                         DESK           4           parent concept                                      PENCIL         4           parent concept                                      INSULATOR      1           element concept                                     COMBUSTIBILITY 1           element concept                                     PLANT          2           element concept                                     GRAVITY OF     1           element concept                                     1 OR LESS                                                                      ______________________________________                                    

"COMBUSTIBILITY" is an element concept of "PLANT" and corresponds to an indirect element concept of "WOOD", while it does not show in the retrieval results on the basis of the step explained in STEP-S124.

For example, when the data to be retrieved is "PLANT", results shown in Table 19 can be obtained.

                  TABLE 19                                                         ______________________________________                                         Data identification                                                                           Data                                                            name of extracted data                                                                        level       Classification of                                   string         value       concept                                             ______________________________________                                         WOOD           3           parent concept                                      DESK           4           indirect parent                                                                concept                                             PENCIL         4           indirect parent                                                                concept                                             COMBUSTIBILITY 1           element concept                                     ______________________________________                                    

In Example 8, the data retrieval method can be carried out according to the scrap method explained in Example 3 or Example 6. For example, when the data to be retrieved are "WOOD" and "MICA", results shown in Table 20 can be obtained.

                  TABLE 20                                                         ______________________________________                                         Data identification name                                                                        Hit number of inputted                                        of extracted data string                                                                        data strings                                                  ______________________________________                                         DESK             1                                                             PENCIL           1                                                             INSULATOR        2                                                             COMBUSTIBILITY   1                                                             PLANT            1                                                             SPECIFIC GRAVITY OF                                                                             1                                                             1 OR LESS                                                                      ______________________________________                                    

EXAMPLE 9

Example 9 is concerned with the data retrieval method directed to the fourth aspect of the present invention. In Example 9, the data string structure in the data structure and various data stored in the data strings are the same as those in Example 8.

In the data retrieval method in Example 9, first, a data identification name to be retrieved is inputted. Then, a data string is extracted on the basis of the link-information data stored in the element data storage area of the data string whose data identification name storage area stores the inputted data identification name, and a data string is further extracted on the basis of the link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty. The above data retrieval can be carried out by means of the third retrieving pattern shown in FIGS. 3A and 3B or the fourth retrieving pattern shown in FIG. 4.

Then, a data string is extracted on the basis of the link-information data stored in the parent data storage area of the data string whose element data storage area is empty from among the data strings extracted in the above step, and a data string is further extracted on the basis of the link-information data stored in the parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty. Then, the so-extracted data string is outputted. The above data retrieval can be carried out by means of the first retrieving pattern shown in FIGS. 1A and 1B and explained in Example 1 or the second retrieving pattern shown in FIG. 2 and explained in Example 2.

Specifically, for evaluating the data string as to whether or not the element data storage area is empty, it is sufficient to use a dynamic array D' which is to store not only ID number in the dynamic array D explained in Example 5 but also a data level value (see FIGS. 22 and 23). And, the retrieving pattern 3 explained in Example 5 is completed, and then a new dynamic array D' composed of the dynamic array D(0) and a data level value of "1" is formed. Then, with the data identification name corresponding to the ID number stored in the above new dynamic array D' is used as a data identification name to be retrieved, for example, the retrieving process 1 (see FIG. 9) explained in Example 1 is executed. And, a data string corresponding to the ID number stored in the dynamic array D' (i) is extracted (read out) from the data structure in the same manner as in STEP-S17 in Example 1, and the data identification name stored in the data identification name storage area and the data level value stored in the data level storage area of the above data string can be displayed, for example, on the display unit 16.

For example, when the data to be retrieved is "WOOD", the new dynamic array D' having contents shown in Table 21 can be obtained. Further, retrieval results shown in Table 22 can be obtained. The data level values are arranged in the ascending order when the retrieval results are outputted.

                  TABLE 21                                                         ______________________________________                                                D'(0)      ID number = 12                                                      D'(1)      ID number = 5                                                       D'(2)      ID number = 6                                                       D'(3)      ID number = 8                                                ______________________________________                                    

                  TABLE 22                                                         ______________________________________                                         Data identification name                                                       of extracted data string                                                                         Data level value                                             ______________________________________                                         INSULATOR         1                                                            COMBUSTIBILITY    1                                                            SPECIFIC GRAVITY OF                                                                              1                                                            1 OR LESS                                                                      PLANT             2                                                            MICA              2                                                            WOOD              3                                                            DESK              4                                                            PENCIL            4                                                            ______________________________________                                    

In Example 9, the data retrieval method can be carried out on the basis of the new dynamic array D' according to the scrap method explained in Example 3. In this case, data strings based on ID numbers which are contents of the new dynamic array D' are consecutively extracted (read out) from the data structure, the read-out data string is stored in the variable storage area as an inputted data string, and then the procedures in STEP-S43 in Example 3 and the procedures thereafter can be carried out.

EXAMPLE 10

Example 10 is concerned with the link-information adding method directed to the third aspect of the present invention, and with a link-information adding method of adding new link-information data to the parent data storage area of a data string. In Example 10, the data string structure of in the data structure and various data stored in the data strings are the same as those in Example 1. Fundamentally, the link-information adding method in Example 10 can be said to be similar to the first link-information adding method of the present invention explained in Example 4. Therefore, the link-information adding method in Example 10 will be explained particularly with regard to points different from the first link-information adding method of the present invention explained in Example 4, with reference to flow charts of FIGS. 15 to 18.

As shown in FIG. 15, first, a data identification name is inputted through the input unit 12 containing, e.g., a keyboard, and a parent concept name indicating a set which includes the data identification name is also inputted (STEP-S70). In Example10, as new link-information data, the link-information data about the data string of ID number 7 storing the data identification name "Plant" will be added to the data string of ID number 6 storing the data identification name "COMBUSTIBILITY". That is, the concept name "PLANT" corresponds to a parent concept, and the concept name "COMBUSTIBILITY" corresponds to an element concept.

MPU 10 reads the inputted letter strings "COMBUSTIBILITY" and "PLANT", and stores them in the variable storage areas established in the main storage device 14. MPU 10 checks whether the inputted data identification name is in agreement with the inputted parent concept name (STEP-S71), and when they are in agreement, MPU 10 discontinues the addition of link-information data since the already explained Rule (2) is violated. When the inputted data identification name is not in agreement with the inputted parent concept name, MPU 10 extracts (reads out) the inputted data string DS₋₋ I (ID number 6) which is a data string storing the inputted data identification name, and also extracts (reads out) the parent concept data string DS₋₋ P (ID number 7) which is a data string storing the data identification name in agreement with the inputted parent concept name (STEP-S72, STEP-S73).

Then, MPU 10 checks whether the parent data storage area of the inputted data string DS₋₋ I has the link-information data about the parent concept data string DS₋₋ P (STEP-S74). If affirmative, MPU 10 discontinues the addition of link-information data since the already explained Rule (1) is violated. The above checking can be also conducted by deciding whether the link-information data about the inputted data string DS₋₋ I is stored in the element data storage area of the parent concept data string DS₋₋ P.

When the link-information data about the parent concept data string DS₋₋ P is not there in the parent data storage area of the inputted data string DS₋₋ I, MPU 10 conducts the checking of Rule (3). That is, a data string is extracted on the basis of the link-information data stored in the parent data storage area of the parent concept data string DS₋₋ P, and a data string is further extracted on the basis of the link-information data stored in the parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty (STEP-S75). In the above retrieval step, the data strings of ID numbers 15 and 16 are extracted.

When any one of the data strings extracted in the above retrieval step is in agreement with the inputted data string DS₋₋ I (ID number 6), the addition of the link-information data is discontinued since Rule (3) is violated (STEP-S76).

When none of the data strings extracted in the above retrieval step is in agreement with the inputted data string DS₋₋ I (ID number 6), ID number 7 which is the link-information data about the parent concept data string DS₋₋ P is stored in the parent data storage area of the inputted data string DS₋₋ I (STEP-S77). Further, ID number 6 which is the link-information data about the inputted data string DS₋₋ I is stored in the element data storage area of the parent concept data string DS₋₋ P (ID number 7) (STEP-S77).

Then, MPU 10 executes the data level value adjustment in STEP-S78. That is, as shown in FIG. 16, MPU 10 compares the data level value of the inputted data string DS₋₋ I (ID number 6) with the data level value of the parent concept data string DS₋₋ P (ID number 7). More specifically, MPU 10 compares the value of the data level storage area Level₋₋ X! of the inputted data string stored in a variable X of the main storage device 14 with the value of the data level storage area Level₋₋ Y! of the parent concept data string stored in a variable Y (STEP-S80). The variables X and Y have the same structure as those of the variables X and Y explained in Example 4. When the value of the data level storage area Level₋₋ Y!≦the value of the data level storage area Level₋₋ X!, a value obtained by adding 1 to the value of the data level storage area Level₋₋ X! is stored in the data level storage area Level₋₋ Y! (STEP-S81). In Example 10, since the value of the data level storage area Level₋₋ Y! is equal to the value of the data level storage area Level₋₋ Y!, "2" is stored in the data level storage area Level₋₋ Y!.

Then, MPU 10 writes the contents of the variables X and Y in the data strings of corresponding ID numbers in the data structure (STEP-S82).

Then, a data string is extracted on the basis of the link-information data stored in the parent data storage area of the parent concept data string DS₋₋ P (ID number 7). When the data level value of the so-extracted data string is equal to, or smaller than the data level value adjusted in STEP-S78 (data level value obtained after the adjustment in STEP-S81), a value obtained by adding 1 to the data level value adjusted in STEP-S78 is stored in the data level storage area of the so-extracted data string. That is, the data level value of the data string of ID number 7 changes from "1" to "2", which changes the data level value of the data string (ID number 12 in Example 10) storing the data identification name indicating a set which includes the data identification name stored in the data string of ID number 7. Further, there is a change in the data level values of the data strings (data strings of ID numbers 15 and 16 in Example 10) storing the data identification name indicating a set which includes the data identification name stored in the data string of ID number 12. It is therefore necessary to carry out the data level value readjustment procedure (STEP-S79).

In the above case, a data string is extracted on the basis of the link-information data stored in the parent data storage area of the data string storing the data identification name corresponding to the parent concept name, and a data string is further extracted on the basis of the link-information data stored in the parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty. When the data level value of the extracted data string (DS-E) is equal to, or greater than, the data level value of the data string (DS-F) extracted on the basis of the link-information data stored in the parent data storage area of the data string (DS-E), a value obtained by adding 1 to the data level value of the extracted data string (DS-E) is stored in the data level storage area of the data string (DS-F).

The above can be carried out by executing STEP-S90 to STEP-S102 in Example 4 explained with reference to FIGS. 17 and 18. Accordingly, the addition of the new link-information data to the parent data storage area of the data string is completed.

EXAMPLE 11

Example 11 is a variant of Example 10, and is concerned with the link-information adding method directed to the fourth aspect of the present invention.

In Example 10 which is concerned with the link-information adding method directed to the third aspect of the present invention, in STEP-S75, a data string is extracted on the basis of the link-information data stored in the parent data storage area of the parent concept data string DS₋₋ P. That is, the above step is substantially the same as STEP-S13 to STEP-S16 in Example 1. On the other hand, in the link-information adding method in Example 11, in STEP-S75, a data string is extracted on the basis of the link-information data stored in the element data storage area of the inputted data string DS₋₋ I.

That is, in the link-information adding method in Example 11, in STEP-S74, it is checked whether the element data storage area of the parent concept data string DS₋₋ P has the link-information data about the inputted data string DS₋₋ I. If the link-information data is there, the addition of the link-information data is discontinued since Rule (1) is violated. The above checking can be also conducted by deciding whether the link-information data about the parent concept data string DS₋₋ P is stored in the parent data storage area of the inputted data string DS₋₋ I.

When the element data storage area of the parent concept data string DS₋₋ P has no link-information data about the inputted data string DS₋₋ I, the checking of Rule (3') is conducted. That is, a data string is extracted on the basis of the link-information data stored in the element data storage area of the inputted data string DS₋₋ I, and a data string is further extracted on the basis of the link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty. Specifically, MPU 10 executes the already explained third retrieving pattern or fourth retrieving pattern on the basis of the data of the element identification number storage area Element₋₋ ID₋₋ X! of the element data storage area Element₋₋ X! of the data string stored in the variable X of the main storage device 14. Since the data string of ID number 6 storing the data identification name "COMBUSTIBILITY" has a data level value of "1", no data string is extracted in the above retrieval step.

When any one of the data strings extracted in the above step is in agreement with the data string DS₋₋ P storing the parent concept name (ID number 7 in Example 11), the addition of the link-information data is discontinued. When none of the data strings extracted in the above step is in agreement with the data string DS₋₋ P storing the parent concept name, ID number 7 which is the link-information data about the data string DS₋₋ P storing the parent concept name is stored in the parent data storage area of the inputted data string DS₋₋ I (ID number 6) (STEP-S77). Further, ID number 6 which is the link-information data about the inputted data string DS₋₋ I is stored in the element data storage area of the data string DS₋₋ P (ID number 7) storing the parent concept name.

Except for the above point, other steps in Example 11 can be the same as those in Example 10, and their detailed explanation is therefore omitted.

EXAMPLE 12

Example 12 is concerned with the link-information adding method directed to the fifth aspect of the present invention, and is concerned with the link-information adding method of adding new link-information data to the element data storage area of a data string. In Example 12, the data string structure in the data string and various data stored in data strings are the same as those in Example 1. Fundamentally, the link-information adding method in Example 12 can be said to be similar to the second link-information adding method of the present invention explained in Example 7. Therefore, the link-information adding method in Example 12 will be explained particularly with regard to points different from the second link-information adding method of the present invention explained in Example 7, with reference to flow charts of FIGS. 25 and 26 and FIGS. 17 and 18.

As shown in FIG. 25, first, a data identification name is inputted through the input unit 12 containing, e.g., a keyboard, and an element concept name which is an element of a set indicated by the data identification name is also inputted (STEP-S140). In Example 12, as new link-information data, the link-information data about the data string of ID number 6 (element concept data string, DS₋₋ E) storing the data identification name "COMBUSTIBILITY" is added to the data string (inputted data string, DS₋₋ I) of ID number 7 storing the data identification name "PLANT". MPU 10 reads the inputted letter strings "PLANT" and "COMBUSTIBILITY" and stores them in the variable storage areas established in the main storage device 14. MPU 10 checks whether the inputted data identification name is in agreement with the inputted element concept name (STEP-S141), and when they are in agreement, the addition of the link-information data is discontinued since Rule (2) is violated.

When the inputted data identification name is not in agreement with the inputted element concept name, the inputted data string DS₋₋ I (ID number 7) which is the data string storing the inputted data identification name is extracted, and the element concept data string DS₋₋ E (ID number 6) which is the data string storing the data identification name in agreement with the inputted element concept name is extracted (STEP-S142 and STEPS-143).

Then, it is checked whether the element data storage area of the inputted data string DS₋₋ I has the link-information data about the element concept data string DS₋₋ E (STEP-S144). If the above is the case, the addition of the link-information data is discontinued since Rule (1) is violated. This decision can be also conducted by checking whether the link-information data about the inputted data string DS₋₋ I is stored in the parent data storage area of the element concept data string DS₋₋ E.

When the link-information data about the element concept data string DS₋₋ E is not there in the element data storage area of the inputted data string DS₋₋ I, the checking of Rule (3) is conducted. That is, a data string is extracted on the basis of the link-information data stored in the parent data storage area of the inputted data string DS₋₋ I, and a data string is further extracted on the basis of the link-information data stored in the parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty (STEP-S145). Unlike Example 7, the above step can be substantially the same as STEP-S13 to STEP-S16 in Example 1. In the above retrieval step, the data strings of ID numbers 12, 15 and 16 are extracted.

When any one of the data strings extracted in the above retrieval step is in agreement with the element concept data string DS₋₋ E (ID number 6), the addition of the link-information data is discontinued since Rule (3') is violated (STEP-S46).

When none of the data strings extracted in the above retrieval step is in agreement with the element concept data string DS₋₋ E (ID number 6) storing the element concept data identification name, ID number 6 which is the link-information data about the element concept data string DS₋₋ E is stored in the element data storage area of the inputted data string DS₋₋ I (ID number 7) (STEP-S147). ID number 7 which is the link-information data about the inputted data string DS₋₋ I is also stored in the parent data storage area of the element concept data string DS₋₋ E (ID number 6). The above step can be also the same as STEP-S147 in Example 7.

Then, MPU 10 executes the data level value adjustment in STEP-S148. That is, as shown in FIG. 26, MPU 10 compares the data level value of the inputted data string DS₋₋ I (ID number 7) with the data level value of the element concept data string DS₋₋ E (ID number 6). More specifically, MPU 10 compares the value of the data level storage area Level₋₋ X! of the inputted data string stored in a variable X of the main storage device 14 with the value of the data level storage area Level₋₋ Y! of the element concept data string stored in a variable Y (STEP-S150). The variables X and Y have the same structures as those explained in Example 7. When the value of the data level storage area Level₋₋ X!≦the value of the data level storage area Level₋₋ Y!, a value obtained by adding 1 to the value of the data level storage area Level₋₋ Y! is stored in the data level storage area Level₋₋ X! (STEP-S151). In Example 12, since the value of the data level storage area Level₋₋ X! is equal to the value of the data level storage area Level₋₋ Y!, "2" is stored in the data level storage area Level₋₋ X!.

Then, the contents of X and Y are written in the data strings of the corresponding ID numbers in the data structure (STEP-S152).

Then, if necessary, a data string is extracted on the basis of the link-information data stored in the parent data storage area of the data string DS₋₋ I, and a value obtained by adding 1 to the data level value of the data level storage area Level₋₋ X! is stored in the data level storage area of the extracted data string when the extracted data string has a data level value equal to, or smaller than, the value of the data level storage area Level₋₋ X!.

That is, a data string is extracted on the basis of the link-information data stored in the parent data storage area of the inputted data string DS₋₋ I (ID number 7), and when the data level value of the so-extracted data string is equal to, or smaller than, the data level value adjusted in STEP-S151, a value obtained by adding 1 to the data level value adjusted in STEP-S151 is stored in the data level storage area of the so-extracted data string. That is, the data level value of the data string of ID number 7 changes from "1" to "2", which causes a change in the data level value of the data string (ID number 12 in Example 12) storing the data identification name indicating a set which includes the data identification name stored in the data string of ID number 7. Further, there is also caused a change in the data level values of the data strings (data strings of ID numbers 15 and 16 in Example 12) storing the data identification name indicating a set which includes the data identification name stored in the data string of ID number 12. It is therefore required to conduct the data level value readjustment procedure.

In the above case, a data string is extracted on the basis of the link-information data stored in the parent data storage area in the parent concept data string, and a data string is further extracted on the basis of the link-information data stored in the parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty. When the data level value of the extracted data string (DS-G) is equal to, or greater than, the data level value of the data string (DS-H) extracted on the basis of the link-information data stored in the parent data storage area of the extracted data string (DS-G), a value obtained by adding 1 to the data level value of the extracted data string (DS-G) is stored in the data level storage area of the data string (DS-H).

The above can be carried out by executing STEP-S90 to STEP-S102 in Example 4 explained with reference to FIGS. 17 and 18. In this case, however, the content of the variable X is moved to the variable Y before STEP-S90 is executed. The addition of new link-information data to the element data storage area of the data string is accordingly completed.

EXAMPLE 13

Example 13 is a variant of Example 12, and is concerned with the link-information adding method directed to the sixth aspect of the present invention.

In Example 12 which is concerned with the link-information adding method directed to the fifth aspect of the present invention, in STEP-S145, a data string is extracted on the basis of the link-information data stored in the parent data storage area of the inputted data string DS₋₋ I. That is, the above step is substantially the same as STEP-S13 to STEP-S16. On the other hand, in the link-information adding method in Example 13, in STEP-S145, a data string is extracted on the basis of the link-information data stored in the element data storage area of the element concept data string DS₋₋ E.

That is, in the link-information adding method in Example 13, in STEP-S145, when the parent data storage area of the element concept data string DS₋₋ E has no link-information data about the inputted data string DS₋₋ I (or when the element data storage area of the inputted data string DS₋₋ I has no link-information data about the element concept data string DS₋₋ E), a data string is extracted on the basis of the link-information data stored in the element data storage area of the element concept data string DS₋₋ E, and a data string is further extracted on the basis of the link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty. Specifically, the third retrieving pattern or the fourth retrieving pattern which has been already explained is executed on the basis of the data of the element identification number storage area Element₋₋ ID₋₋ Y! of the element data storage area Element₋₋ Y! of the data string stored in a variable Y of the main storage device 14. Since the data level value of the data string of ID number 6 storing the data identification name "COMBUSTIBILITY" is "1", no data string is extracted in the above retrieval step.

When any one of the data strings extracted in the above step is in agreement with the inputted data string DS₋₋ I (ID number 7 in Example 13) (STEP-S146), the addition of the link-information data is discontinued. When none of the data strings extracted in the above step is in agreement with the inputted data string DS₋₋ I, ID number 6 which is the link-information data about the element concept data string DS₋₋ E is stored in the element data storage area of the inputted data string DS₋₋ I (ID number 7) (STEP-S147). Further, ID number 7 which is the link-information data about the inputted data string DS₋₋ I is stored in the parent data storage area of the element concept data string DS₋₋ E (ID number 6).

Except for the above points, other steps are the same as those in Example 12, and detailed explanation of the other points is therefore omitted.

EXAMPLE 14

Example 14 is concerned with the data retrieval method directed to the first and fourth aspects of the present invention, more specifically to the first and fourth aspects in the medical field of diagnostics. Table 23 shows a data structure in Example 14.

It is diagnostically very useful to know any possible disease on the basis of symptoms which a patient has and test data obtained by examining the patient. A medical doctor can know what is a disease

                                      TABLE 23                                     __________________________________________________________________________        Concept Name Recorded    Element                                            ID in Data String           Concept Name                                       No.                                                                               3rd level 2nd level                                                                               1st level                                                                            2nd level                                                                               1st level                                 __________________________________________________________________________     1                     fever                                                    2                     leukocytosis                                             3                     leukopenia                                               4                     cough                                                    5                     sputa                                                    6            viral.sub.-- pneumonia  fever                                                                          leukopenia                                                                     cough                                     7            respiratory sympton     cough                                                                          sputa                                     8  bacterial.sub.-- pneumonia        fever                                                                          leukocytosis                                                          respiratory sympton                                __________________________________________________________________________

which has leukocytosis, cough and fever as element concepts and/or indirect element concepts when he or she can extract, from a data structure, a data string having a data identification name which can be a parent concept and/or an indirect parent concept with regard to the concepts of leukocytosis, fever and cough. That is, "LEUKOCYTOSIS", "FEVER" and "COUGH" are inputted as data identification names to be retrieved. Table 24 shows results of the data retrieval carried out according to the data retrieval method of the scrap method. For specific data retrieval procedures, please refer to Example 3.

                  TABLE 24                                                         ______________________________________                                                            Hit number of                                               Data identification name                                                                          inputted                                                    of extracted data string                                                                          data strings                                                ______________________________________                                         BACTERIAL PNEUMONIA                                                                               3                                                           VIRAL PNEUMONIA    2                                                           RESPIRATORY SYMPTOM                                                                               1                                                           ______________________________________                                    

The results of the above data retrieval show that the concept having all of "LEUKOCYTOSIS", "FEVER" and "COUGH" as element concepts and/or indirect element concepts is "BACTERIAL PNEUMONIA". The above "BACTERIAL PNEUMONIA" does not contains "COUGH" as an element concept. It is however seen that since "RESPIRATORY SYMPTOM" contains "COUGH" as an element concept, "BACTERIAL PNEUMONIA" has "COUGH" as an indirect element concept.

When all of diseases are expressed as data strings having a data level value of "2" and the data retrieval is conducted, the same result as above can be obtained. However, an element set is full of a list of symptoms and abnormal qualities identified in a test, stored in first level data strings, and it is therefore difficult to identify the characteristics of a disease. More rational is a method in which a disease is expressed by means of medical concepts which can express the characteristics and in which the used medical concepts are expressed by other medical concepts.

In diagnostics, it is necessary to consider a case where a patient has no typical symptoms. In this case, for example, it is necessary to expand the retrieval scope to diseases having at least two symptoms of "LEUKOCYTOSIS", "FEVER" and "COUGH" as element concepts and/or indirect element concepts. The data identification names showing that the hit number of the inputted data strings is at least "2" are "VIRAL PNEUMONIA" and "BACTERIAL PNEUMONIA".

When a disease showing a respiratory symptom is retrieved, a medical doctor sometimes needs only a disease having one of "COUGH" and "SPUTA" as an element concept and/or an indirect element concept. For example, the concept of "VIRAL PNEUMONIA" contains the concept of "COUGH" alone out of "COUGH" and "SPUTA". Originally, the element set of the "VIRAL PNEUMONIA" should be

{FEVER, LEUKOPENIA, COUGH, SPUTA}

or

{FEVER, LEUKOPENIA, RESPIRATORY SYMPTOM}.

At the stage of forming the data structure, however, the above consistency is not always satisfied.

In the application of the data retrieval method directed to the fourth aspect of the present invention explained in Example 9, for example, it is possible to determine a concept which has at least one element concept and/or indirect element concept of "RESPIRATORY SYMPTOM" as an element concept and/or an indirect element concept. That is, as a result of the data retrieval, "VIRAL PNEUMONIA" and "BACTERIAL PNEUMONIA" can be obtained. However, the display of "respiratory symptom" and "first level data string" is excluded.

Further, there is a problem concerning synonyms. For example, various expressions such as "FEVER", "HIGH FEVER" and "LOWER GRADE FEVER" are used, and these terms are distinguished depending upon diseases when used. When it is supposed to retrieve feverish disease, it is required to combine "FEVER", "HIGH FEVER" and "LOWER GRADE FEVER" by "OR" in the a conventional retrieval method. In contrast, in the data retrieval method of the present invention, a data string

FEVER {HIGH FEVER, LOWER GRADE FEVER}

which corresponds to a concept including similar concepts is formed in advance. And, the data retrieval method directed to the fourth aspect of the present invention is carried out, whereby all of feverish diseases having "FEVER", "HIGH FEVER" and "LOWER GRADE FEVER" as element concepts and/or indirect element concepts can be obtained. Data strings defined as concepts including synonyms are prepared in advance, whereby the omission of designated keywords or the complicated designation of items can be avoided.

EXAMPLE 15

Example 15 is concerned with the data retrieval method directed to the second aspect of the present invention. Example 15 deals with the following chemical reactions.

MgO+H₂ →Mg+H₂ O

C+O₂ →CO₂

CO₂ +H₂ O→H₂ CO₃

Table 25 shows the data structure in Example 15.

In Table 25, a compound which is a data identification name stored in a certain data string having a certain data level value is formed by a reaction of a certain compound or element which is a data identification name stored in a data string

                  TABLE 25                                                         ______________________________________                                         Concept Name Recorded in Data                                                  ID   String               Element Concept Name                                 No.  3rd level 2nd level 1st level                                                                             2nd level                                                                              1st level                              ______________________________________                                         1                        MgO                                                   2                        H.sub.2                                               3                        C                                                     4                        O.sub.2                                               5              Mg                       MgO                                                                            H.sub.2                                6              H.sub.2 O                MgO                                                                            H.sub.2                                7              CO.sub.2                 C                                                                              O.sub.2                                8    H.sub.2 CO.sub.3           CO.sub.2                                                                       H.sub.2 O                                      ______________________________________                                    

corresponding to link-information data stored in the element data storage area of the certain data string.

In Example 15, "H₂ CO₃ " is inputted as data to be retrieved. As data retrieval results after the procedures similar to those in Example 5, "MgO", "H₂ ", "C" and "O₂ " can be obtained when only data strings having a data level value of "1" are displayed. These results show that H₂ CO₃ is formed from MgO, H₂, C and O₂.

The present invention is explained on the basis of preferred embodiments of the present invention, while the present invention shall not be limited to these embodiments. The data string structure in the data structure is give for an illustrative purpose, and can be properly modified. The retrieval data array and retrieval element data array are also given for an illustrative purpose, and can be properly modified. Further, the method of extracting data strings is also given for an illustrative purpose, and data strings can be extracted by any method.

For example, a data structure shown in FIG. 33 may be used. The data structure shown in FIG. 33 contains a concept structure, a parent set structure and an element set structure. In the concept structure, each data string contains an identification number storage area ID!, a data identification name storage area Name!, a level value storage area Level!, a parent data storage area Parent! and an element data storage area Element!. In the identification number storage area ID!, an identification number for identifying the data string is stored. The identification number is a number characteristic of its corresponding data string. In a data identification name storage area Name!, a concept name at a corresponding level (first level concept name, second level concept name, third level concept name, etc.) is stored. In the data level value storage area Level₋₋ Value!, the data level value (1, 2, 3 or the like of the data string is stored.

The parent data storage area Parent! is composed of a parent concept link-information data count area Parent₋₋ Count! for storing the count number of the parent concept link-information data, a parent set structure link-information data first storage area Parent₋₋ LinkTop! for storing ID number at the head of the related parent set structure, and a parent set structure link-information data second storage area Parent₋₋ LinkEnd! for storing ID number at the end of the related parent set structure. When there is no related parent set structure, "void" is written in the parent set structure link-information data first storage area Parent₋₋ LinkTop! and the parent set structure link-information data second storage area Parent₋₋ LinkEnd!.

The element data storage area Element! is composed of an element concept link-information data count area Element₋₋ Count! for storing the number of the element concept link-information data, an element set structure link-information data first storage area Element₋₋ LinkTop! for storing ID number at the head of the related element set structure, and an element set structure link-information data second storage area Element₋₋ LinkEnd! for storing ID number at the end of the related element set structure. When there is no element set structure, "void" is written in the element set structure link-information data first storage area Parent₋₋ LinkTop! and the element set structure link-information data second storage area Parent₋₋ LinkEnd!.

The parent set structure is composed of an ID number storage area ID! for storing ID number, a next ID number storage area Next₋₋ ID! for storing ID number of a next parent set structure, a previous ID number storage area Before₋₋ ID! for storing ID number of a parent set structure located before the present parent set structure, and parent identification number storage areas Parent₋₋ ID!. The next parent set structure is used when the present parent set structure cannot manage to store parent concept link-information data, that is, when the parent identification number storage areas Parent₋₋ ID! in the present parent set structure are full. In the parent identification number storage areas Parent₋₋ ID!, ID numbers as parent concept link-information data are stored.

The element set structure is composed of an ID number storage area ID! for storing ID number, a next ID number storage area Next₋₋ ID! for storing ID number of a next element set structure, a previous ID number storage area Before₋₋ ID! for storing ID number of an element set structure located before the present element set structure, and element identification number storage areas Element₋₋ ID!. The next element set structure is used when the present element set structure cannot manage to store element concept link-information data, that is, when the element identification number storage areas Element₋₋ ID! in the present element set structure are full. In the element identification number storage areas Element₋₋ ID!, ID numbers are stored as element concept link-information data.

In the data structure having the above structure, a data identification name is inputted and a data string (inputted data) having a concept structure storing the data identification name is accordingly read out. A data of the parent set structure can be arrived at on the basis of the ID number stored in the parent set structure link-information data first storage area Parent₋₋ LinkTop! of the inputted data string. The content of the data of the above parent set structure is read out, whereby the link-information data about the parent concept can be read out. When the parent identification number storage area Parent₋₋ ID! alone is not adequate for storing link-information data, the data of the parent set structure can be read out on the basis of ID number stored in the next ID number storage area Next₋₋ ID!. In the element set structure, link-information data of an element concept can be also similarly read out.

In the data retrieval method or the link-information adding method of the present invention, the possibility of falling in an endless loop in data retrieval can be completely prevented. Further, the circulating definition can be completely removed. In adding link-information data in the data structure, users can add link-information data without taking care not to cause a circulating definition. Further, there are excellent effects that not only a parent concept and an element concept can be extracted, but also an indirect parent concept and an indirect element concept can be extracted, in the data retrieval.

According to the present invention, there can be constructed a data structure for effectively and easily expressing knowledge in the form of a hierarchical structure. In this data structure, all pieces of knowledge is modeled by means of a set having a name called a concept, and users can construct and reconstruct a data structure having a hierarchical structure as required. The direct or indirect circulating definition which takes place when a certain concept as an element concept is added to other concept can be automatically excluded. 

What is claimed is:
 1. A link-information adding method of adding new link-information data to a data string in a data-string set consisting of a plurality of data strings,each data string DS₋₋ 1 having(1) a data identification name storage area storing a data identification name, (2) a data level storage area storing a data level value, and (3) a parent data storage area storing link-information data about a data string DS₋₋ 2 storing the data identification name which indicates a set including the data identification name stored in the data string DS₋₋ 1, wherein:(A) the data string DS₋₋ 2 has a greater data level value than the data string DS₋₋ 1 has, (B) the parent data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the parent data storage area of the data string DS₋₋ 1 differ from one another, and (C) when data strings are consecutively traced on the basis of link-information data stored in parent data storage areas of data strings, with arbitrary link-information data stored in the parent data storage area of the data string DS₋₋ 1 as a starting point, until the parent data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the parent data storage areas of the traced data strings, the method comprising the steps of(a) inputting a data identification name and a parent concept name which indicates a set including the data identification name, (b) adding no link-information data when the inputted data identification name and the inputted parent concept name are in agreement with each other, (c) extracting a data string DS₋₋ I storing the inputted data identification name when the inputted data identification name and the inputted parent concept name are not in agreement with each other, (d) extracting a data string DS₋₋ P storing the data identification name which is in agreement with the inputted parent concept name, (e) adding no link-information data when the parent data storage area of the data string DS₋₋ I extracted in the step (c) has link-information data about the data string DS₋₋ P extracted in the step (d), (f) extracting a data string on the basis of link-information data stored in the parent data storage area of the data string DS₋₋ P extracted in the step (d) when the parent data storage area of the data string DS₋₋ I extracted in the step (c) has no link-information data about the data string DS₋₋ P extracted in the step (d), and further extracting a data string on the basis of the link-information data stored in the parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty, (g) adding no link-information data when any one of the data strings extracted in the step (f) is in agreement with the data string DS₋₋ I extracted in the step (c), (h) storing link-information data about the data string DS₋₋ P extracted in the step (d) to the parent data storage area of the data string DS₋₋ I extracted in the step (c) when none of the data strings extracted in the step (f) is in agreement with the data string DS₋₋ I extracted in the step (c), and (i) storing a value obtained by adding 1 to the data level value of the data string DS₋₋ I extracted in the step (c) in the data level storage area of the data string DS₋₋ P extracted in the step (d) when the data string DS₋₋ P extracted in the step (d) has a data level value equal to, or smaller than, the data level value of the data string DS₋₋ I extracted in the step (c).
 2. A link-information adding method of adding new link-information data to a data string in a data-string set consisting of a plurality of data strings,each data string DS₋₋ 1 having(1) a data identification name storage area storing a data identification name, (2) a data level storage area storing a data level value, and (3) an element data storage area storing link-information data about a data string DS₋₋ 0 storing a data identification name which is an element of a set indicated by the data identification name stored in the data string DS₋₋ 1, wherein:(A) the data string DS₋₋ 0 has a smaller data level value than the data string DS₋₋ 1 has, (B) the element data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the element data storage area of the data strings DS₋₋ 1 differ from one another, and (C) when data strings are consecutively traced on the basis of link-information data stored in element data storage areas of data strings, with arbitrary link-information data stored in the element data storage area of the data string DS₋₋ 1 as a starting point, until the element data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the element data storage areas of the traced data strings, the method comprising the steps of(a) inputting a data identification name and an element concept name which is an element of a set indicated by the data identification name, (b) adding no link-information data when the inputted data identification name and the inputted element concept name are in agreement with each other, (c) extracting a data string DS₋₋ I storing the inputted data identification name when the inputted data identification name and the inputted element concept name are not in agreement with each other, (d) extracting a data string DS₋₋ E storing the data identification name which is in agreement with the inputted element concept name, (e) adding no link-information data when the element data storage area of the data string DS₋₋ I extracted in the step (c) has link-information data about the data string DS₋₋ E extracted in the step (d), (f) extracting a data string on the basis of link-information data stored in the element data storage area of the data string DS₋₋ E extracted in the step (d) when the element data storage area of the data string DS₋₋ I extracted in the step (c) has no link-information data about the data string DS₋₋ E extracted in the step (d), and further extracting a data string on the basis of the link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty, (g) adding no link-information data when any one of the data strings extracted in the step (f) is in agreement with the data string DS₋₋ I extracted in the step (c), (h) storing link-information data about the data string DS₋₋ E extracted in the step (d) to the element data storage area of the data string DS₋₋ I extracted in the step (c) when none of the data strings extracted in the step (f) is in agreement with the data string DS₋₋ I extracted in the step (c), and (i) storing a value obtained by adding 1 to the data level value of the data string DS₋₋ E extracted in the step (d) in the data level storage area of the data string DS₋₋ I extracted in the step (c) when the data string DS₋₋ E extracted in the step (d) has a data level value equal to, or greater than, the data level value of the data string DS₋₋ I extracted in the step (c).
 3. A link-information adding method of adding link-information data to a data string in a data-string set consisting of a plurality of data strings,each data string DS₋₋ 1 having(1) a data identification name storage area storing a data identification name, (2) a data level storage area storing a data level value, (3) a parent data storage area storing link-information data about a data string DS₋₋ 2 storing a data identification name which indicates a set including the data identification name stored in the data string DS₋₋ 1, and (4) an element data storage area storing link-information data about a data string DS₋₋ 0 storing a data identification name which is an element of a set indicated by the data identification name stored in the data string DS₋₋ 1, wherein:(A) the data string DS₋₋ 2 has a greater data level value than the data string DS₋₋ 1 has, (B) the parent data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the parent data storage area of the data string DS₋₋ 1 differ from one another, (C) when data strings are consecutively traced on the basis of link-information data stored in parent data storage areas of data strings, with arbitrary link-information data stored in the parent data storage area of the data string DS₋₋ 1 as a starting point, until the parent data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the parent data storage areas of the traced data strings, (D) the data string DS₋₋ 0 has a smaller data level value than the data string DS₋₋ 1 has, (E) the element data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the element data storage area of the data strings DS₋₋ 1 differ from one another, and (F) when data strings are consecutively traced on the basis of link-information data stored in element data storage areas of data strings, with arbitrary link-information data stored in the element data storage area of the data string DS₋₋ 1 as a starting point, until the element data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the element data storage areas of the traced data strings, the method comprising the steps of(a) inputting a data identification name and a parent concept name which indicates a set including the data identification name, (b) adding no link-information data when the inputted data identification name and the inputted parent concept name are in agreement with each other, (c) extracting a data string DS₋₋ I storing the inputted data identification name when the inputted data identification name and the inputted parent concept name are not in agreement with each other, (d) extracting a data string DS₋₋ P storing the data identification name which is in agreement with the inputted parent concept name, (e) adding no link-information data when the parent data storage area of the data string DS₋₋ I extracted in the step (c) has link-information data about the data string DS₋₋ P extracted in the step (d), (f) extracting a data string on the basis of link-information data stored in the parent data storage area of the data string DS₋₋ P extracted in the step (d) when the parent data storage area of the data string DS₋₋ I extracted in the step (c) has no link-information data about the data string DS₋₋ P extracted in the step (d), and further extracting a data string on the basis of the link-information data stored in the parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty, (g) adding no link-information data when any one of the data strings extracted in the step (f) is in agreement with the data string extracted DS₋₋ I in the step (c), (h) storing link-information data about the data string DS₋₋ P extracted in the step (d) in the parent data storage area of the data string DS₋₋ I extracted in the step (c) when none of the data strings extracted in the step (f) is in agreement with the data string DS₋₋ I extracted in the step (c), (i) storing link-information data about the data string DS₋₋ I extracted in the step (c) in the element data storage area of the data string DS₋₋ P extracted in the step (d), and (j) storing a value obtained by adding 1 to the data level value of the data string DS₋₋ I extracted in the step (c) in the data level storage area of the data string DS₋₋ P extracted in the step (d) when the data string DS₋₋ P extracted in the step (d) has a data level value equal to, or smaller than, the data level value of the data string DS₋₋ I extracted in the step (c).
 4. A link-information adding method of adding link-information data to a data string in a data-string set consisting of a plurality of data strings,each data string DS₋₋ 1 having(1) a data identification name storage area storing a data identification name, (2) a data level storage area storing a data level value, (3) a parent data storage area storing link-information data about a data string DS₋₋ 2 storing a data identification name which indicates a set including the data identification name stored in the data string DS₋₋ 1, and (4) an element data storage area storing link-information data about a data string DS₋₋ 0 storing a data identification name which is an element of a set indicated by the data identification name stored in the data string DS₋₋ 1, wherein:(A) the data string DS₋₋ 2 has a greater data level value than the data string DS₋₋ 1 has, (B) the parent data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the parent data storage area of the data string DS₋₋ 1 differ from one another, (C) when data strings are consecutively traced on the basis of link-information data stored in parent data storage areas of data strings, with arbitrary link-information data stored in the parent data storage area of the data string DS₋₋ 1 as a starting point, until the parent data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the parent data storage areas of the traced data strings, (D) the data string DS₋₋ 0 has a smaller data level value than the data string DS₋₋ 1 has, (E) the element data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the element data storage area of the data strings DS₋₋ 1 differ from one another, and (F) when data strings are consecutively traced on the basis of link-information data stored in element data storage areas of data strings, with arbitrary link-information data stored in the element data storage area of the data string DS₋₋ 1 as a starting point, until the element data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the element data storage areas of the traced data strings, the method comprising the steps of(a) inputting a data identification name and a parent concept name which indicates a set including the data identification name, (b) adding no link-information data when the inputted data identification name and the inputted parent concept name are in agreement with each other, (c) extracting a data string DS₋₋ I storing the inputted data identification name when the inputted data identification name and the inputted parent concept name are not in agreement with each other, (d) extracting a data string DS₋₋ P storing the data identification name which is in agreement with the inputted parent concept name, (e') adding no link-information data when the element data storage area of the data string DS₋₋ P extracted in the step (d) has link-information data about the data string DS₋₋ I extracted in the step (c), (f') extracting a data string on the basis of link-information data stored in the element data storage area of the data string DS₋₋ I extracted in the step (c) when the element data storage area of the data string DS₋₋ P extracted in the step (d) has no link-information data about the data string DS₋₋ I extracted in the step (c), and further extracting a data string on the basis of the link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty, (g') adding no link-information data when any one of the data strings extracted in the step (f') is in agreement with the data string DS₋₋ P extracted in the step (d) and (h') storing link-information data about the data string DS₋₋ P extracted in the step (d) in the parent data storage area of the data string DS₋₋ I extracted in the step (c) when none of the data strings extracted in the step (f') is in agreement with the data string DS₋₋ P extracted in the step (d), (i) storing link-information data about the data string DS₋₋ I extracted in the step (c) in the element data storage area of the data string DS₋₋ P extracted in the step (d), and (j) storing a value obtained by adding 1 to the data level value of the data string DS₋₋ I extracted in the step (c) in the data level storage area of the data string DS₋₋ P extracted in the step (d) when the data string DS₋₋ P extracted in the step (d) has a data level value equal to, or smaller than, the data level value of the data string DS₋₋ I extracted in the step (c).
 5. A link-information adding method of adding new link-information data to a data string in a data-string set consisting of a plurality of data strings,each data string DS₋₋ 1 having(1) a data identification name storage area storing a data identification name, (2) a data level storage area storing a data level value, (3) a parent data storage area storing link-information data about a data string DS₋₋ 2 storing the data identification name which indicates a set including the data identification name stored in the data string DS₋₋ 1, and (4) an element data storage area storing link-information data about a data string DS₋₋ 0 storing the data identification name which is an element of a set indicated by the data identification name stored in the data string DS₋₋ 1, wherein:(A) the data string DS₋₋ 2 has a greater data level value than the data string DS₋₋ 1 has, (B) the parent data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the parent data storage area of the data string DS₋₋ 1 differ from one another, (C) when data strings are consecutively traced on the basis of link-information data stored in parent data storage areas of data strings, with arbitrary link-information data stored in the parent data storage area of the data string DS₋₋ 1 as a starting point, until the parent data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the parent data storage areas of the traced data strings, (D) the data string DS₋₋ 0 has a smaller data level value than the data string DS₋₋ 1 has, (E) the element data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the element data storage area of the data string DS₋₋ 1 differ from one another, and (F) when data strings are consecutively traced on the basis of link-information data stored in element data storage areas of data strings, with arbitrary link-information data stored in the element data storage area of the data string DS₋₋ 1 as a starting point, until the element data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the element data storage areas of the traced data strings, the method comprising the steps of(a) inputting a data identification name and an element concept name which is an element of a set indicated by the data identification name, (b) adding no link-information data when the inputted data identification name and the inputted element concept name are in agreement with each other, (c) extracting a data string DS₋₋ I storing the inputted data identification name when the inputted data identification name and the inputted element concept name are not in agreement with each other, (d) extracting a data string DS₋₋ E storing the data identification name which is in agreement with the inputted element concept name, (e) adding no link-information data when the element data storage area of the data string DS₋₋ I extracted in the step (c) has link-information data about the data string DS₋₋ E extracted in the step (d), (f) extracting a data string on the basis of link-information data stored in the parent data storage area of the data string DS₋₋ I extracted in the step (c) when the element data storage area of the data string DS₋₋ I extracted in the step (c) has no link-information data about the data string DS₋₋ E extracted in the step (d), and further extracting a data string on the basis of the link-information data stored in the parent data storage area of the extracted data string until the parent data storage area of the extracted data string is empty, (g) adding no link-information data when any one of the data strings extracted in the step (f) is in agreement with the data string DS₋₋ E extracted in the step (d), (h) storing link-information data about the data string DS₋₋ E extracted in the step (d) in the element data storage area of the data string DS₋₋ I extracted in the step (c) when none of the data strings extracted in the step (f) is in agreement with the data string DS₋₋ E extracted in the step (d), (i) storing link-information data about the data string DS₋₋ I extracted in the step (c) in the parent data storage area of the data string DS₋₋ E extracted in the step (d), and (j) storing a value obtained by adding 1 to the data level value of the data string DS₋₋ E extracted in the step (d) in the data level storage area of the data string DS₋₋ I extracted in the step (c) when the data string DS₋₋ E extracted in the step (d) has a data level value equal to, or greater than, the data level value of the data string DS₋₋ I extracted in the step (c).
 6. A link-information adding method of adding new link-information data to a data string in a data-string set consisting of a plurality of data strings,each data string DS₋₋ 1 having(1) a data identification name storage area storing a data identification name, (2) a data level storage area storing a data level value, (3) a parent data storage area storing link-information data about a data string DS₋₋ 2 storing the data identification name which indicates a set including the data identification name stored in the data string DS₋₋ 1, and (4) an element data storage area storing link-information data about a data string DS₋₋ 0 storing the data identification name which is an element of a set indicated by the data identification name stored in the data string DS₋₋ 1, wherein:(A) the data string DS₋₋ 2 has a greater data level value than the data string DS₋₋ 1 has, (B) the parent data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the parent data storage area of the data string DS₋₋ 1 differ from one another, (C) when data strings are consecutively traced on the basis of link-information data stored in parent data storage areas of data strings, with arbitrary link-information data stored in the parent data storage area of the data string DS₋₋ 1 as a starting point, until the parent data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the parent data storage areas of the traced data strings, (D) the data string DS₋₋ 0 has a smaller data level value than the data string DS₋₋ 1 has, (E) the element data storage area of the data string DS₋₋ 1 does not contain link-information data about the data string DS₋₋ 1 itself, and the link-information data stored in the element data storage area of the data string DS₋₋ 1 differ from one another, and (F) when data strings are consecutively traced on the basis of link-information data stored in element data storage areas of data strings, with arbitrary link-information data stored in the element data storage area of the data string DS₋₋ 1 as a starting point, until the element data storage area of the traced data string is empty, the link-information data about the data string DS₋₋ 1 is included in none of the element data storage areas of the traced data strings, the method comprising the steps of(a) inputting a data identification name and an element concept name which is an element of a set indicated by the data identification name, (b) adding no link-information data when the inputted data identification name and the inputted element concept name are in agreement with each other, (c) extracting a data string DS₋₋ I storing the inputted data identification name when the inputted data identification name and the inputted element concept name are not in agreement with each other, (d) extracting a data string DS₋₋ E storing the data identification name which is in agreement with the inputted element concept name, (e') adding no link-information data when the parent data storage area of the data string DS₋₋ E extracted in the step (d) has link-information data about the data string DS₋₋ I extracted in the step (c), (f') extracting a data string on the basis of link-information data stored in the element data storage area of the data string DS₋₋ E extracted in the step (d) when the parent data storage area of the data string DS₋₋ E extracted in the step (d) has no link-information data about the data string DS₋₋ I extracted in the step (c), and further extracting a data string on the basis of link-information data stored in the element data storage area of the extracted data string until the element data storage area of the extracted data string is empty, (g') adding no link-information data when any one of the data strings extracted in the step (f') is in agreement with the data string DS₋₋ I extracted in the step (c), and (h') storing link-information data about the data string DS₋₋ E extracted in the step (d) in the element data storage area of the data string DS₋₋ I extracted in the step (c) when none of the data strings extracted in the step (f') is in agreement with the data string DS₋₋ I extracted in the step (c), (i) storing link-information data about the data string DS₋₋ I extracted in the step (c) in the parent data storage area of the data string DS₋₋ E extracted in the step (d), and (j) storing a value obtained by adding 1 to the data level value of the data string DS₋₋ E extracted in the step (d) in the data level storage area of the data string DS₋₋ I extracted in the step (c) when the data string DS₋₋ E extracted in the step (d) has a data level value equal to, or greater than, the data level value of the data string DS₋₋ I extracted in the step (c). 